Shot a little today

Tomme boy

Well-Known Member
Took the AR15 350 Legend and the Savage Axis 223 bolt rifle out for a little bit today.

I started out shooting the Savage today with the Mihec 65gr 227 bullet. I sized to 0.225" and checked with a Gator copper check. Powder coated in Smokes purple one coat. Checks were put on before the powder coat then sized again. Then switched to the Legend with a 200gr hp RCBS checked and powder coated shot in a AR15 with a 16" barrel

I have seen lots of people mention RL7 and I have a bunch of this so why not. I went from 15gr-19gr in a 0.5gr jump. I also loaded an extra one to run through the AR to check to see if it locked back. It did not lock back till 18gr. This is on a 11.5" pistol. Carbine gas. The Savage rifle has a 22" 1-9 twist barrel with a muzzle brake. It is a Boyds laminate Tac/Var stock. This gun normally shoots about 0.75-0.90" groups with jacketed.

223 DATA. 4 shot groups.
  1. 15gr NO DATA
  2. 15.5GR 2281FPS 13ES 7SD
  3. 16GR NO DATA
  4. 16.5GR 2396FPS 41ES 17SD
  5. 17GR 2451FPS 42ES 18SD
  6. 17.5GR 2525FPS 30ES 15SD
  7. 18GR 2570FPS 29ES 13SD
  8. 18.5GR 2631FPS 40ES 17SD
  9. 19GR 2682FPS 15ES 7SD
350 LEGEND data. I think I need to switch to a mag primer as there was a drop in velocity and was getting high ES.

  1. 24gr 1859fps 51es 28sd
  2. 24.5gr 1900fps 30es 16sd
  3. 25gr 1915fps 29es 16sd
  4. 25.5gr 1887fps 52es 28sd
  5. 26gr 1903fps 61es 30sd
  6. 26.5gr 1925fps 43es 21sd
  7. 27gr 1951fps 51es 28sd PRIMERS STARTING TO FLATTEN
  8. 27.5GR 1974fps 23es 11sd



Kevin Stenberg

Well-Known Member
Tomme I am impressed with the velocity and accuracy. Even at the low end just shy of 2400fps and a 2" group with a first try. Not to shabby.


Residing in New England

Im relieved to see same kinda groups produced from my rifles. (Hoping both coulda been better)

I finally got my 350 Upper assembled. (Maybe ya saw my post on Bushcraft)
My first targets where not much to brag upon.
BUT, 27g under a 190 Ranch Dog produced a 50y Clover.


Im only 65/70 bullets thru barrel and just did second cleaning. BUT the barrel is quite slick already.
Tomorrow gonna stop on my way home and send 40 more down range and then scrub again.

Tomme boy

Well-Known Member
350 is 16"
556 is 11.5"

I was just checking for function with this one. Should have said there was this gun also. Since I was not actually putting it on paper I failed to mention it. This gun has had about 100 rds shot through it. I have seen a few post where RL7 was used and a 55gr cast and had full function at 15grs. Not this one. I guess the gas port is not as worn as the other guns that were mentioned. Some of the guns mentioned were 10.5" and had even a shorter dwell time at the port. A worn gas port would increase diameter and allow more gas to operate the action.


Well-Known Member
You're still limited by gas tube dia. AND length (8"). I use rx7 in BO with carbine gas but barrel is longer. If you run the 556 fast the short barrel dumps pressure before the bolt cycles. So you increase powder (pressure) so bolt cycles before bullet leaves barrel.
Last edited:
  • Like
Reactions: Ian

Tomme boy

Well-Known Member
Gas port on this barrel was 0.065" if I remember right when I put it together. Most are around 0.700+ unless it is for a suppressed gun. Then they run in the 0.600-0.620" area to start out at. I think bore diameter has a effect on the amount of gas also. So the 300 would have more gas and a longer dwell time as it is a slower bullet.

I have some RL10X that I am going to try next. It has given me some very good groups shooting jacketed. I have several 556 ar's. I figure that I would get this one to shoot first. If this one works then the others should as they are a mix of 16" barrels. Two are mid-length and they might be a problem also.

@popper I know you have done a lot of work on the 300, so any advise that would carry over would be great. I cast up about 700 of the 224 bullets today to get started. I have close to 300 that are ready to go right now. I am also going to open up my sizing die just a hair. It is sizing the bullets to 0.2245" My chamber will allow a lot larger. I am going to shoot for 0.2255" or 0.226". i have to check the bolt gun for size I don't want to have different bullets for each gun. Hoping to find a happy medium for all of them.
Last edited:


Notorious member
Watch that 10x near the top end, it can get really stupid and run away with pressure, at least it did in my .35 Remington. QL predicted it would so I was careful but it spiked about a grain early.


Well-Known Member
IMHO the gas only unlocks the bolt.
Edit: (recalculated my numbers-sorry - shoulda taken fluid dynamics class)
Assume 10k port/case head psi. IIRC Army specs 12k.
Bolt piston (223) = ~700#, case head = ~2k#
Piston (308) = ~800#, case head = ~4k#.
Volume of bolt piston/cylinder increases so psi is greatly reduced (f(A*p)=vT) which occurs in a very short time. As soon as case 'shrinks' to release, effective 'blow back' action! Over pressure can rip rims, under pressure and short-stroke occurs (port/barrel pressure too low or too short). We try to adjust to 'our' load with buffer and gas (mass flow rate - E=MV = work!).
Visualize how the system works, then what to 'tune'.

Solutions ?
Slower powder, heavier/slower bullet, run the BCG really wet!. Something like the Kaw Valley Lin Comp. may help due to baffle that keeps barrel pressure up.
Hope that helps some.

Shot BO pistol with 170gr RD, ammo worked fine. 308W I used a grain to much Imr4895 - no leading but no accuracy @50. Shot 40sw no-aim from waist - I really need more practice!!
Last edited:

Tomme boy

Well-Known Member
Loading for the 556 guns tonite

Loaded up 10 ea with imr4198 in 0.5gr increases from 17gr-19gr. And 10 ea with imr4895 from 19gr-21.5gr in 0.5gr increases. Going to try 5 each in the ar15 pistol with the 11.5" barrel and 5 each in the Savage bolt rifle.

I weighed out the 224 bullets and they are coming in at 63.4gr-63.6gr. Thats powder coated and copper checked. I sorted these out before powder coat so if any defect they went back in the pot. They were perfect or they went back. That must be why they only were 0.2grs spread. The PC is pretty even and not thick. I shake them off pretty well in a wire mesh colander. I don't stand them up at all, dump and bake.

Now to see if the new chronograph works out. I downloaded the app on my phone and on one of my tablets. They paired right up on both. This is the Competition Electronics bluetooth model. It has some really neat features you can enter all kinds of variables into it for data. Can take a pic of each group to link with each string. I am going to like that. It will make a log much easier.