Bushmaster Carbine - Change Parts?

[M4arc]

The Crane O ring and Defender are brands (Crane is actually a command) but any of the dealers here can get you pointed in the right direction. An H buffer denotes the weight of a buffer; LMT and Colt make them.

The heavier buffer and M16 do indeed slow the cycling down. It helps smooth things out.

[Low Drag]

The Crane O ring and Defender are brands (Crane is actually a command) but any of the dealers here can get you pointed in the right direction. An H buffer denotes the weight of a buffer; LMT and Colt make them.

The heavier buffer and M16 do indeed slow the cycling down. It helps smooth things out.

Thanks for the straight up info.

One more quesiton if I could.

Does slowing the cycle rate decrease the limited recoil of the 5.56, aiding in follow up shots as well as inproving extraction reliabiliy?

[C4IGrant]

Thanks for the straight up info.

One more quesiton if I could.

Does slowing the cycle rate decrease the limited recoil of the 5.56, aiding in follow up shots as well as inproving extraction reliabiliy?

Slowing the cyclic rate does NOT decrease recoil, but generally to get the rate down, you would use a heavier buffer. This DOES reduce felt recoil. A heavier buffer will also allow for faster follow up shots IMHO.



C4

[Low Drag]

Slowing the cyclic rate does NOT decrease recoil, but generally to get the rate down, you would use a heavier buffer. This DOES reduce felt recoil. A heavier buffer will also allow for faster follow up shots IMHO.



C4

I figured the heavy buffer would slow the cycle rate and decrease recoil just a bit.

I also noticed my extractor when cleaning. I did see some brass shavings under the extractor. I take it this is a symtom of the slippage you guys are refering to. I've had no extraction issue to this point and well over 500 rds fired.

[jmart]

Some report heavier buffers increase recoil, or at least muzzle rise. Some competition guns run adjustable gas blocks with lightweight BCGs. They recoil pretty quickly but they stay on target. Very similar to comp handguns running LW springs. They cycle quickly but they stay on target.

[Cameron]

[Hoplophile]

Some competition guns run adjustable gas blocks with lightweight BCGs.

Some of those are running ammo loaded so light that the weapon won't function with normal weight parts.

[Robb Jensen]

Some of those are running ammo loaded so light that the weapon won't function with normal weight parts.

Exactly. If this is a carbine used for defensive and training purposes I highly recommend a H2, H3 or Enidine buffer w/ISMI springs, carbines are cycling too fast already.
Making a carbine cycle faster by using a lighter carrrier & buffer is counter productive to reliability.

In a competition gun some do use the adjustable gas blocks and JP or other lightened carriers and buffers. I tried an adjustable gas block and JP lighter carrier and buffer in my 3 gun 20" AR and I couldn't get it to run correctly. I then Rocksetted the gas block fully open, I run a JP full weight stainless carrier and a rifle length Enidine buffer. The theory is that a lightened carrier and buffer will produce less felt recoil because of the lighter mass moving in the gun and because it's in motion for a shorter amount of time. Honestly I couldn't feel much difference and I shoot about 1K rounds ever 2 months in this gun. It's running 100% now. I use factory loaded American Eagle 55gr FMJ in it for matches.

[M193 BALL]

I've heard/read a ton from Colt AR15 fans regarding the other AR makers "low quality". Some folks suggest replacing the some of the "cheap" parts but I've not seen much in the way of specifics.


1) So what parts if any need/should be replaced in a Bushmaster carbine?
2) Why?

I'm open to suggestions.

Thanks in advance.

I was very Skeptical about buying a Bushmaster back in 2000

I was a COLT ONLY GUY

I was lucky with my 2 BUSHMASTERS

My Bushy Shorty eats all different types of 223/5.56 ALL UP
I have under 5000 rds FIRED without a single malfuntion!!

the Same with my bushy 20 hbar


I SOLD the Bushy 20HBAR because I needed some extra cash

Still have the Bushy Shorty A1 ( but put the upper away )


Back in Feb 06 I bought a LMT14.5 M4 upper to replace the Shorty Upper

I also added a VLTOR and a 551 EOTECH

I like this set up alot better than the Shorty upper because its LITE

BTW the LMT has M 4 ramps and a 1/7 twist

Since the LMT M4 upper rans so good
I ennded up buying a Complete LMT M4 w/ SOPMOD stock



I wouldnt change anything with your Bushmaster.
Mine ran fine as is.

Maybe a VLTOR or SOPMOD stock

and if you MUST then just buy a LMT M4 Upper they are CLOSE to COLT Quality

[jmart]

Some of those are running ammo loaded so light that the weapon won't function with normal weight parts.

Do competition guns have to meet a power factor? If so, what kind of velocity is needed for a 55 grain load?

ETA: Just looked up IPSC rules and to make minor (150 PF), you'd need to load to about 2730 fps for a 55 grain pill. That's about 250 fps under 16" barrel spec velocity for XM-193, and probably around Wolf/Federal AE spec loadings.

Not suggesting someone outfit their fighting carbine with JP stuff, I was just commenting on the change in recoil from going either heavier or lighter than stock.