That's where I go thanks. I haven't received any newsletters recently, so I'd better go sign up again.
Thanks loads.
Thanks loads.
Does the velocity of this round, compared to earlier tests, indicate an error with earlier velocities? You've used the same charge, but the velocity is 300fps lower. It's easy to miss a keystroke (7 is above 4), or misread a 4 as a 7, especially if there is a defect in the LCD display. Still having a hard time believing 2,700fps velocities with a 147gr. bullet. Sub 2,400 is much easier to believe.
I understand the inclination to think it is an error, but it isn’t. Those velocities from the 2700 test were verified multiple times in multiple rifles and multiple chronos. The 2400 from this test was verified on two chronos across multiple shots. Historically speaking, bonded/gold dot bullets have always been slower than standard jacketed in pistol and rifle tests, which could be a partial culprit. These were the same lot of powder, same brass, same primers, same rifle. Sometimes funky things just happen, this is certainly one of them.
The one concerning thing is that lower velocities will lead to higher pressures with same weight projectiles (all else being equal). If the bullet seating depths result in the same volume within the case, which your charges of 28.5 gr. would suggest (XTP, HST and now the GD), then only friction is left as a major variable. In that case lower velocities would be due to higher friction. If effective case volume is equal, I would expect that the lower velocities would result in pressures that are significantly higher, on the order of 5-10k, the same general effect as bumping up projectile weight to 170-180. If the case volume is varying due to different seating depths, then all bets are off. Since I'm loading for an AR, I don't have the flexibility of seating depth that you do. I've also seen enough weird data with regards to Lil" Gun so that I'll be staying away from it for this cartridge.
I'm loading for an 8" barrel, so I'll be using slightly faster powder. I'm currently working with Enforcer, but I'll go to AA #7 or 572 with lighter bullets if necessary.
Stay safe.
I'm loading for an 8" barrel, so I'll be using slightly faster powder. I'm currently working with Enforcer, but I'll go to AA #7 or 572 with lighter bullets if necessary.
Stay safe.
I have tested the loads in AR15 and Ruger bolt action platforms (both using AR mag lengths), neither has given me any issues with pressure/over pressure, and primers are identical between the three different loads in both platforms. I have no experience with the powders you listed, but I can say from personal experience that h110/296 is very temperaments and caused me to discontinue all testing with it early on in this caliber. It’s was very touchy compared to the others.
I wouldn't go with 296 either, it's too slow for an 8" barrel with light bullets. I used it a lot for heavy bullets in .357 and .45LC, but I just think this is too long a case for it, don't need the fireball either. Also, living in AZ, temperature sensitivity is something that I'm going to have to look out for. I shoot PCC in competition. In the summer the aluminum handguards get so hot, we need to wear gloves. In the AR the mag length isn't an issue with these stubbly bullets, feeding is the issue. I have a Ruger AR. They really messed-up the extension feed ramps. It was originally cut with standard 5.56 ramps. I sent it back and they did some work, but it still wouldn't feed anything. I had to have a local smith work on it. I have a custom upper being built that I'll be concentrating on. Once I decide on loads for it, I'll go back to the Ruger and see what it needs to work right.
This will cure the vast amount of feeding issues. The 350 case shape is full diameter much further forward than the 223 meaning the case will need to come free of the magazine lips sooner. Grind the feed lips back this far. This is a CMMG magazine.
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how far approx is that ? thanks
I'm currently using the Wilson-modified Lancer mags, I find that they feed better than the others. I'll wait until I get my new upper before I do anything to the mags, if needed I'll modify them as necessary. With the Ruger there is also slop in the seating of the mags. When they don't feed I tap the bottom of the mag and the round goes right in. It looks like the mags may be sitting .020-.030 too low.
Thanks.
