12/4/2023 0 Comments 240 grain 308 subsonic loadsSome of the research I found from finland and GB had pointed to a design like that being used in gallery loads of the early 1900's. Let me know the results, that makes sense. I would order another, but FEDX has a 50 Alaskan barrel headed this way that I know I can get the right recipe and suppress it to around 125-130 with coolant. I'm wishing I had ordered a few extra inches on this barrel. At the current temperatures, I would expect the barrel to cool down to ambient temp within 15 min. Then spend most of the day measuring cold bore shots. Consequently, I'm going to start over with new brass and a vise rest. My biggest gripe is vertical stringing and the first round sometimes dumping. Which is fine, I don't plan on using it past 200 anyway. I'm shooting an encore pistol, so I don't think I should expect much better than 1 MOA. After the pierced primer, I stoped testing and played with my GAPs.Įver tried Unique or Redot? MAybe a blend of TB and a faster powder? Not because of the peircing, but I've used it on my 16" 1/10 with 10.5 gr and the case volume is too low to get any consistency unless you tip the rifle barrel up to get the powder against the primer (then it will actually will shoot 20 rounds into a dime at 100 and 2" at 200, but I'm not likely to do this when in the field when I usually raise my barrel to the target from the shoulder). I'll pull the rest of this load, and will probably not use greendot again. The 240's with 15.0 greendot pierced the primer on the second shot with no vel reading. The 220 Hornady RN SP's shot fairly well with 14.0 gr TB getting me 975 fps, grouping was about 2" at 100. I only had a few rounds remaining of 200's so I'll need to order some more to get a better picture. The 200 SMKs and 13.0 TB were right at 1040fps and grouped around 1.75". It could also be my crony and where I'm placing the bullet through the screens-not totally sure. I think it's blowing a lot of powder into the suppressor and igniting there. I tried 14, 14.5 and 15.0 and the velocity actually went down as I went up in charge. With the 240s and TB, I maxed out in vel at 13.0 grains. The first cold bore shot is slower, today I shot about 50 different rounds with mixes of TB, Greendot, and Unique with 240 and 200 SMKs and 220 RNSP. (a guess Do you have a longer barrel? And are you seeing a significant speed difference between the first shot (cold barrel) versus a second and third shot? My calculation for the 240gr SMK was hypothetical based on a ratio of what is good for a 175 versus a 220gr SMK. The Editor over at 6MMBR website mentioned he used the dry lube to reduce his SD, so I am going to try it. Since I use an Ultrasonic cleaner to clean brass, there is no burnt powder residue left inside the case. I just ordered some Neoconos Special Carbon Steel Dry Neck Lube to try and bring down the SD by lubing the inside of the neck. Reasonably accurate but not as good as 175 SMK.Ģ20gr SMK 13.0 gr of Trailboss, 1020 fps but with a high SD, pretty good accuracy. Very accurate.ġ80gr Sierra RoundNose, 10.8 gr of Trailboss, ~1050 fps and SD 30. My loads: (I use LR primers and not Magnum primers)ġ75gr SMK 10.8 gr of Trailboss, 1064 fps and SD 14. However, I did not get any keyholing with 220's. Actually, according to the stability calculator, 220's are marginal with 1in10. I was just working up a load for the 220gr SMKs, and have not used the 240's because the bullet is too long for my twist rate. I have an 18" barrel, DPMS LR308B with 1in10 twist.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |