Weight sorted cases ..

[Ian]

The square base of the bullet and the square base of the breech seating tool ensure that the bullet slips into the center of the throat and squares up as the bullet begins to engrave. There is a BIG difference between a square rod pushing the bullet and gas pressure that is desperately trying to find the path of least resistance around the bullet.

Using just the right proportion and pre-compression of a compacting, granulated buffer in between the powder and bullet inside of a bottleneck case will come close to doing the same thing as a breech seater and the effect shows on targets.

I firmly believe based on primer and inert, simulated powder charge loads that the primer alone breech seats a powder coated bullet very straight in the throat before the powder would light, provided that the static fit is exactly centered (i.e. case fits the chamber closely, neck is in the center, chamber/throat/bore are concentric with each other, and the bullet is seate straight in line with the case) AND the bullet is allowed some free movement before contacting the throat. My kingdom for a window into the throat and a million FPS camera!

 

[Bret4207]

Not to worry Ian. My cousins best friends sisters boyfriends uncle Larry told him his barbers son inlaws brothers taxidermist has an app on his phone that does just that. It's in Google Play someplace...

 

[Snakeoil]

I envisioned what was going on with the breech seating method. And the proof is in the pudding using my friends' .25-20SS results. But I can also envision the soft lead bullet lying cockeyed partly in the throat and starting into the lands and continuing in cockeyed until the flat base of the seating ram forces the bullet to line up. But that same process will probably also smear some lead on the edge of the flat base as it aligns. A breech-seater that actually holds the bullet straight so it enters straight has a better chance of zero damage and hence consistent point of impact, IMHO. Again, newbie envisioning what is going on. It may not make a huge difference in group size, and you might have to shoot several hundred rounds using each method before you can conclusively say whether or not it makes a difference.

Regarding a quasi-breech-seating method using the powder in a case, that is how I shot BPCR for many years. I never sized my .45-70 cases and my bullets were a slip fit into the case mouth. I compressed my powder with a die I made so that when I closed the breechblock on the Shiloh I could feel the powder crunch just a tad as it pushed the bullet into the lands. Many of us shot using this method. And the results spoke for themselves when the NRA came to Wilton to investigate because our match scores were much higher than other NRA match scores. They thought our yardages were short or we were doing something illegal. They found nothing wrong. Our shooters were simply figuring out how to do it. With time others did at well and as many here know, the scores required to meet the various classifications got bumped up. I had just made it into master class when they bumped up the scores. I got over it.

 

[Ian]

So we've pretty much established that neck tension consistency (even virtually NO tension) and getting the bullet into the throat absolutely square, in line, and straight are key factors to accuracy. Again. This concept has been well established for over 100 years but it is highly perishable information.

There is another factor affecting cast bullet groups which has been baffling me for decades but I think I got it sorted out from secondary indicators. Something happening farther up the barrel even with perfectly started bullets which gives us an accurate velocity limitation. Jackets of any sort mitigate it (paper, copper, or polymer). What is it? It pretty much HAS to be the un-jacketed bullet wearing away on the drive side of the engraves. How this wear and gas cutting affects groups I don't exactly know, but it does. I have to powder coat all the bullets used in suppressors or lead accumulates in them rapidly, almost as bad as .22 rimfire suppressors and for the same reason. Powder coating doesn't 100% eliminate this dusting (especially at extremely high velocity) but it helps reduce it tremendously and allows jacketed velocity or higher with reasonable group sizes and no fancy case or neck prep.

Most of you are probably sick of seeing these photos but here they are again. These groups were shot at 100 yards from an LR-308, suppressed, 18" barrel, 2460 fps, and the brass was same-lot WCC military range pickup brass that had about 1.5 thousandths average neck thickness variation but was only prepped by uniforming length, VLD inside deburring, outside deburring, swaging and uniforming the primer pockets, and sizing for .002" headspace via an RCBS GMM full-length neck sizing die and a bushing that gave minimal tension for the expander to bring up a couple thousandths to uniform size/tension. The bullets were sized .3095" and the throat entrance is about .3102". Bullets were seated "just" off the throat, not really sure how much, maybe 1.5 turns of the Forster BR seating die micrometer (guess I could read the marks, but I just make a dummy and chamber it and give the seater a couple twists after the fully-chambered cartridge falls out of a clean chamber by gravity). Soooo, what matters most with fixed ammunition? Dynamic fit and a jacket. I didn't weigh bullets (three cavity HP mould), have no idea about case volume other than it is less than commercial, neck thickness all over the place, once-fired brass that had the necks sized too small in the first place. This load shoots 1.3" ten-shot groups over and over and over no matter what the brass used (as long as it's the same lot) or powder charge within three grains.



Cold, clean barrel above and below left. Below left with barrel-mounted chronograph installed, followed by group on right without it.



Since I started powder coating my rifle bullets, I pretty much quit all the time-consuming case prep and fussing and started focusing on loads which would work equally well in a variety of rifles with very different throats and states of wear. This is where a bullet design which maximizes the self-alignment concept shines. The quest for "universal loads" is even more challenging with my fleet of .30-30s, but I got that one whipped too thanks to PC and finding the right bullet shape and seating depth. I'm happy with 1.5" ten-shot groups with no first-shot flyer out of the group from a cold, clean barrel. VERY happy. All this allows me to do more shooting and have more fun without segregating ammunition for every rifle and spending years tweaking loads. Obviously, I don't compete. My primary interest is informal shooting and hunting. YMMV.

 

[Bret4207]

Ian, you brought back a memory when you mentioned the wear on the bullets drive side of the land and gas cutting. I've seen that in print before, not sure if it was Pope, Roberts, Mattern, Naramore or who, but the theory seems a bit older than you and I put together. IIRC that was one of the reasons given for why faster powders were supposedly "better" (???) for cast as the pressure was supposed to drop off faster and not be so prone to gas cutting. Interesting to see the idea come back up- it sure makes sense.

 

[Ian]

I trapped bullets and proved it. Also not the first time that's been done, but maybe the first time it was done at nearly full pressure and velocity for modern rifle cartridges.

 

[burbank.jung]

Ian and Bret. I opened a new thread. Can you answer my question?

 

[Snakeoil]

So, fire all 60 cases in a match yesterday. We had some new steel disc targets made that are sized to be 3 minutes in diameter at the various yardages we shoot. Yesterday was 10 rounds each at 200, 300 and 400 yds with 2 offhand shots at a coyote set at 500. One shooter hit the coyote using a Hungarian PU sniper rifle, complete with original Russian sniper scope.

I had weighed all my bullets to remove that variable. Kept them within =/- 0.5 gr. My groups were good when I did my job. Those 3 minute targets are separating the men from the boys and the good rifles from the great rifles, good loads nothwithstanding.

I had no flyers. The primary condition yesterday was a mirage that was going from L-R and then R-L. There was a mild head wind, but not enough to make a difference. It was -3F when I got to the club and the wind flags were a tad on the crispy side for the first relay. I warmed them up with my hands and they showed some very mild breezes. I started at 400 and missed 2. First shot for score hit the berm at 9:00 with no room. I put a half minute right into the scope and cleaned the next 8. Due to a brain phardt on my part, I only shot 9 rounds and thought I'd shot 10. My spotter was sure he'd not missed scoring a shot. I realized my mistake and took my rifle back out of the rack and proceeded to miss the last shot, again, with no room. Conditions had changed and both of us failed to notice. My brain may have played a role in that miss as well.

When I got home, I tossed the brass into the tumbler and once clean went at them with the small hole gauge. Since using that is a bit of a pain for multiple measurements, I moved to checking the OD of the necks with a mic and found the following.

48 cases - 0.342-0.3425
12 cases - 0.341 - 0.342

Within those ranges the cases were not 100% round. They varied within that range and some of the 12 small ones ended up there because they varied below 0.3410. I would expect the bullet to give and the OD of the case to match the chamber shape in the case of thickness variation within the neck wall. So, it would appear that my chamber is not perfectly round, at least in the neck/throat area.

After doing this I set the small hole gauge to a snug slip fit in a case and then ran it thru all the others. All but a couple had the same feel. My suspicion on the OD variation is either the brass is a tad thinner or the smaller OD cases were shot in the cold rifle for the first relay. Although my rifle goes from the house to a heated vehicle, it was meat locker cold inside the enclosed firing line until we got the wood stove and propane furnace cranked up. So, I suspect my rifle had cooled down prior to the first shots.

The neck IDs I did measure were in the 0.313 - 0.3135 range. My bullet measures 0.3140 so that makes for very little neck tension. I'd like to see 0.002 - 0.003 interference fit. So, my hope to avoid neck sizing was defeated by my chamber dimensions.

My plan is to move to a .303 British collet neck sizer. Using the mandrel dimensions for my .30-06 sizer, I suspect that the mandrel for the .303B will be 0.312. I have a question into Lee asking that question. That should be perfect for my purposes. I have a brand-new collet/mandrel set that Lee sent me when the original started to show wear and was sticking closed and ruining the next case. I thought about opening up the hole in the closer and machining a bigger mandrel. But for the price of a .303B die, simply buying a new die is probably the better route.

A side note on those Lee collet neck sizers. They are NOT hardened. So, if you do not lube them, and I'm not sure that will do much other than prolong the inevitable, they will wear and start to stick. After I got my replacement parts from Lee, I took the old set and polished out the wear on my lathe. Then I case hardened both parts and repolished. They work great and there is no signs of wear or sticking. I do use STP as a lube for the collet to closer surfaces. Bill Wilson mentioned using that on sears in his book some 30 years ago and I've been using it for sears and other sliding high pressure contact surfaces like this since.

 

[burbank.jung]

I once owned a Custome Lee 7.7 collet necks sizing die but being stupid, I damaged it. One thing I discovered about the collet necks sizing die is that it will not resize a neck that is too thick. In short, I had resized LC 30-06 to 7.7 Arisaka cases and had to remove brass at the neck to get the collet die to fit and swage the necks. The brass alone does chamber so I decided to expand the Inside neck dimesions with an RCBS plug.

 

[fiver]

The neck IDs I did measure were in the 0.313 - 0.3135 range. My bullet measures 0.3140 so that makes for very little neck tension. I'd like to see 0.002 - 0.003 interference fit. So, my hope to avoid neck sizing was defeated by my chamber dimensions.

this is close.
if you look at my XCB thread you'll see where i was running about .001 neck tension and seating the bullets long.
each time i closed the bolt the rifling engagement was seating the bullets to the same oal.
i was more concerned with getting the neck tension correct for the bullets diameter than anything else.
i was also using the touching bullets to insure powder pressure rise going to the maximum for each round.
better burn, better ignition [cause nuthin could move until the engraving pressure was overcome]
consistent neck tension.
that meant nothing in terms of bullet release, but it lent itself to feeling the bolt and helping insure the bullets had SOME resistance as the case slid over them.

 

[fiver]

anyway this is kind of reminding me of the old guys debating using a muzzle loader with a false muzzle.
versus.
breech seating with a modern brass case following it up.

i always wonder why someone didn't combine the muzzle loading with a brass case powder holder.
or if they did and it just wasn't worth the trouble.

 

[Ian]

Good to know, Rob. I always assumed the collets were spring steel, so never file checked but when enlarging or shortening went straight to the tool post grinder and used a hose clamp to adjust the finger compression as desired before making round again. In my professional career the standard anti-gall, high-pressure sliding surface lubricant is moly paste, so that's what I use on collet cones and haven't galled one yet. Some are rougher than a cob from the factory and need a little touch-up before use.

 

[Ian]

i always wonder why someone didn't combine the muzzle loading with a brass case powder holder.
or if they did and it just wasn't worth the trouble.

As I recall you never did convince the F&G department to let you hunt with your .30-30 during black powder season if you front-stuffed it.

 

[fiver]

there's this stuff called web grease that all the MEC reloader guys use on their sizing collets.
i'm imagining something like wheel bearing grease full of paratack, but i could be wrong since i only use the ring type sizers.

 

[fiver]

no they didn't buy it.
i tried again this October when i had a chat with both of the local wardens.
one offered to give me a ticket now and i could just pay it when i got around to trying it.

 

[RBHarter]

Pope as I recall did that very thing . I don't remember now for sure if he started the bullet into the bore and chambered the loaded case then pushed the bullet back on to the charge or if he actually pushed it all the way down the bore .

Then there is the stop ring bullets .

 

[RicinYakima]

Pope used a "false Muzzle" and started the bullet from the front with a rod that had a stop. The bullet stopped in the bore just in front of the case. The powder charged case was inserted from the back. The rod and false muzzle were removed and the shot fired.

 

[JWFilips]

Speaking of "False Muzzles": When I built the "Roger's" Heavy Bullet , Flintlock rifle....The customer sent me a custom made "fast twist" rifled barrel along with a matching custom "False Muzzle" for it!
His plan for his dream rifle was a heavy 50 caliber BP bullet rifle to hunt Antelope at long ranges!
I had to be sure that the false muzzle could be used on the rifle I was designing for him.

I can't remember the custom barrel maker he used....It wasn't any of the ones that I bought from & I think it was a modern cartridge rifle barrel maker! I know the Breech plug was a much finer thread then the custom black powder barrel makers use!
I also can't remember the weight of the 50 caliber pure lead bullets he used...but I remember they were hefty.

The last time I was in contact with him he said he was shooting great groups with it a 250 yards off a bench rest with open sights!
He said he was now ready to go out West and hunt some critters!

OK, Sorry for the long story:
But what I get out of all this ....is that the false muzzle held the bullet in perfect alignment with the bore of the rifle and once the bullet engaged the rifling It was pushed to the breach to set on top of the Black powder charge Fully engraving the bullet...then the false muzzle was detached.

 

[Bret4207]

Some used false muzzles and others used a breech seater for the bullet alone. Those Schuetzen boys tried all sorts of interesting ideas.

 

[burbank.jung]

Here is an article I found last night. It's a good article about loading 9mm.

Secrets of reloading for the Colt Combat Commander 9MM auto loader

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