Most of the data I'm finding is for long barrels, around 26". Anybody know what velocity is typical for a 105 hybrid in a 20" barrel? How about an 18" barrel?
- Thread starter Red_SC
- Start date
2750-2800. you lose 20-25fps/inch of barrel.
Gas path length is the big velocity factor here. I've shot 19.5 Grendels with the same load as my 24" barrelled Grendel and the velocity was almost the same. Had to drop one grain and lose 80 FPS going to a medium length gas tube.
I know those are G/LBC numbers but the case is the same and the problem is the same. When the bullet is past the gas port most of the pushing is done.
Now, if it were a bolt gun?....You can cheat a lot of velocity out of a longer barrel.
I know those are G/LBC numbers but the case is the same and the problem is the same. When the bullet is past the gas port most of the pushing is done.
Now, if it were a bolt gun?....You can cheat a lot of velocity out of a longer barrel.
I'd be ecstatic with 2750-2800, I was told 2600 in BHW's board. At that point I'd probably prefer to go with a longer barrel and extended gas system, but I doubt my partner would go for that.
2750 easily attainable from a 20"
6mmar.com has some good info on velocity from ar length barrels.
I did a 23", +2" gas system 6mmAR but have yet to get that one assembled and running.
Buddy did a 20", standard rifle length gas system. He is seeing 2650 - 2700 but still needs to finish up load development. Running 105 Hornady HPBTs IIRC, will pulse him to see. He is running single base powder, could probably pick up another 80-100 fps with double base powder.
105 Hornady BTHP / 105 Berger Match BT / 108 Berger Match BT was better fit to magazine / chamber then the 105 in our chambers (cut by same reamer / smith).
Buddy did a 20", standard rifle length gas system. He is seeing 2650 - 2700 but still needs to finish up load development. Running 105 Hornady HPBTs IIRC, will pulse him to see. He is running single base powder, could probably pick up another 80-100 fps with double base powder.
105 Hornady BTHP / 105 Berger Match BT / 108 Berger Match BT was better fit to magazine / chamber then the 105 in our chambers (cut by same reamer / smith).
FCS, do you know what powders your buddy is using, and the throat specs for the reamer?
The 6mmar.com was one of the ones that had data mostly for 26" barrels.
The 6mmar.com was one of the ones that had data mostly for 26" barrels.
H4895, N-140, Varget to date is what he has tried to best of my memory.
I don't have the reamer print for this chamber, can get you OALs with different bullets to touch lands. Might be few days but I should be able to get those OALs.
I don't have the reamer print for this chamber, can get you OALs with different bullets to touch lands. Might be few days but I should be able to get those OALs.
Is someone building a Woodies DMR rifle Red? 
Yep Jon after this weekend using a set of ar15 for a more local dm match me a Red quessed it mite be a good idea to looking into a semi auto setup for woodys. I suggested that a 223 would probably do the job . We both turned and looked at each other, shuck our heads and said naaaw ( souther word for NOT EVEN GONA HAPPEN)
Last edited:
Try N540 if you can find it. I've seen the best accuracy and velocity from it.
Is someone building a Woodies DMR rifle Red?
That's a possibility! We shot a different DM match with standard AR15's last weekend. Lets just say, the results made us rethink our entire strategy.
Never used N540, I'll start keeping my eyes open for some.
Similar threads
Hunting & Fishing 178 grain ELD-X Performance on Game?
