Gas length

[jakhamr81]

Forgive me if this topic has already been discussed, I couldn't find anything on it, but I was wondering if their was any advantage to using a rifle length or mid length gas system. Could you gain any extra muzzle velocity with the extra length of the rifle system if it kept the bolt in battery just a little longer, or will this have no effect?

 

[pagana]

Re: Gas length

You will not gain extra velocity from using a different port position as the bullet has exited before the bolt unlocks. What you will get is the BCG staying in battery longer thereby slowing the speed at which the action cycles and typically increasing the reliability of a DGI system by virtue of it feeding and extracting more effectively.

 

[AXEMAN]

Re: Gas length

what barrel length are you using? i think heavier carriers, buffers and stiffer springs do more to keep the bolt in battery than the gas port placement. it will have an effect, but using the port placement for this purpose isnt what people seem to do. and barrel length seems to be the deciding factor in gas choice, unless you look around and find someone to make it to your specs. but i have seen 16-18 inches with rifle, mid and carbine length gas ports. i just chose 18" rifle mostly due to wanting an adjustable gas block i could get to, but they usually make the 18" with mid. kreiger offers 16 & 18 in rifle, DPMS only uses carbine for their shorter stuff or rifle for the long ones. i havent seen a DPMS in mid. seems that unlike ar15s there is no real database on what works best and whats to be avoided.

not much help, but thats where i am after a few months or reading stuff. try clicking on my name and viewing my posts for some of the threads about this subject

 

[jakhamr81]

Re: Gas length

I am using a Sabre Defense 18 inc with a mid length gas tube. I bought a case of Black Hills and was disappointed when they chronoed at 2500 fps. I was hoping that their might be a way to get more velocity out of them, but with an 18 inch barrel I think that may be their best performance then.

 

[AXEMAN]

Re: Gas length

i think its been posted that you get or lose 50-75 fps per inch. you could try 155g or start reloading for more speed

 

[jakhamr81]

Re: Gas length

I wish I had the time to reload. Wife, kid, work, and school doesn't leave much time to reload. I barely have enough time to shoot. I'll just have to settle for the factory match ammo until I retire in another 20 years.

 

[AXEMAN]

Re: Gas length

just save your brass at least, sell it to offset the new ammo costs. its not really that much of a chore. break it into small 30 min jobs or how ever much time you can dedicate. if not we have a few guys here that will reload for you. cant recall who they are, but ive seen the chatter in the box. after getting the equipment, im loading "match" ammo for 0.75-0.80 cents a round

 

[jakhamr81]

Re: Gas length

Not a bad idea, I've been just donating it to my fellow shooters. Any idea how much does the lake city brass go for?

 

[DBrace]

Re: Gas length

Save your brass and sell it and buy reloading equiptment. Far more economical then buying "match" grade ammo. That way you can fine tune your load to YOUR gun. You should be able to get $15/100 for uncleaned LC brass. Depending on how much you shoot it should add up quick. RCBS rockchucker kit is a good starter kit for around $300 bones if i remember right.

 

[AXEMAN]

Re: Gas length

i bought 800 1x fired for 0.18 of lake city match from various years.