Strange Beretta Tricompensator

[TopN]

I'm inventorying & organizing (finally ) my BM59 stuff & and I discovered that I had 1 Tricompensator that was different from the others .

 

The pictures show 2 Tricompensators. The longer one is the Standard Italian Infantry & T/A Tricompensator.

 

The Standard Italian Infantry & T/A Tricompensator is about 7 1/8" long (184mm) by my measurements.

 

This Short Tricompensator is only 6 5/32" (160mm ) long.

 

Both are marked P.B. BM59.

 

Both are set up for launching Rifle Grenades - note the Grenade Retaining Spring (Ring) present on both.

 

Both have the Italian Military Bayonet Lug - neither will take modified Garand Bayonets used on most export weapons.

 

Both are used, and came from Italy via my "Dumpster Diving" penpals - presumably off demiled weapons.

 

Again, presumably, this short Tricompensator would require a Flip-Up (Direct-Fire) Grenade Sight that was different from the Standard Infantry/T.A. or the P.C. types of Flip-Up Grenade Sights.

 

Does anybody know what the "short" Tricompensator was used for/on?

 

[winbar]

I'm inventorying & organizing (finally ) my BM59 stuff & and I discovered that I had 1 Tricompensator that was different from the others .

 

The pictures show 2 Tricompensators. The longer one is the Standard Italian Infantry & T/A Tricompensator.

 

The Standard Italian Infantry & T/A Tricompensator is about 7 1/8" long (184mm) by my measurements.

 

This Short Tricompensator is only 6 5/32" (160mm ) long.

 

Both are marked P.B. BM59.

 

Both are set up for launching Rifle Grenades - note the Grenade Retaining Spring (Ring) present on both.

 

Both have the Italian Military Bayonet Lug - neither will take modified Garand Bayonets used on most export weapons.

 

Both are used, and came from Italy via my "Dumpster Diving" penpals - presumably off demiled weapons.

 

Again, presumably, this short Tricompensator would require a Flip-Up (Direct-Fire) Grenade Sight that was different from the Standard Infantry/T.A. or the P.C. types of Flip-Up Grenade Sights.

 

Does anybody know what the "short" Tricompensator was used for/on?

 

Just curious, does the short tricomp have a "booster" chamber before the "brake" chamber?

Doug

[TopN]

Doug,

 

There is a short chamber behind the "pepper-pot"

 

I have no good way of measuring it in comparison to the one in the Standard Length Tricomp.

 

Where did you come across the terms "Booster Chamber" & "Brake Chamber"?

 

"Brake Chamber" is easy to understand, but "Booster Chamber" - what is boosted?

 

But having said that - "Booster Chamber" is a much better description than "that weird milled-out space behind the pepper-pot" .

 

One of my "dumpster-diving" penpals SWAG'ed (SWAG=Scientific Wild-Ass Guess) that the Short Tricomp might have been for the Italian Carabinieri (sort of a cross between State Police, FBI & Army Military Police).

 

TopN

[winbar]

Doug,

 

There is a short chamber behind the "pepper-pot"

 

I have no good way of measuring it in comparison to the one in the Standard Length Tricomp.

 

Where did you come across the terms "Booster Chamber" & "Brake Chamber"?

 

"Brake Chamber" is easy to understand, but "Booster Chamber" - what is boosted?

 

But having said that - "Booster Chamber" is a much better description than "that weird milled-out space behind the pepper-pot" .

 

One of my "dumpster-diving" penpals SWAG'ed (SWAG=Scientific Wild-Ass Guess) that the Short Tricomp might have been for the Italian Carabinieri (sort of a cross between State Police, FBI & Army Military Police).

 

The Beretta brochure(pg.21) says the tricompensator does three things:

-cutting down the recoil

-overcoming the usual upper deflection of the muzzle

-functioning as an effective flashshield

I guess you could call it an anti-recoil chamber(it traps some gas and pushes the gun away from you),

but it also raises the cylic rate. Fire a paracadutisti on full-auto with and without the quick detach and see the difference.

Doug

[TopN]

Doug,

 

I've never fired a BM59 full auto - any idea how it's rate-of-fire compares to a M-14? I was issued & fired F/A a couple of those way way back.

 

Is there any functioning problems - short recoil, etc., with the P.C. when the removeable part of the Tricomp has been taken off?

 

Steve

[winbar]

Doug,

 

I've never fired a BM59 full auto - any idea how it's rate-of-fire compares to a M-14? I was issued & fired F/A a couple of those way way back.

 

Is there any functioning problems - short recoil, etc., with the P.C. when the removeable part of the Tricomp has been taken off?

 

Steve

 

Steve,

 

I can't remember if they put the "knitting needle" (#10 - recoil spring guide, pgs. 51 and 52) in my semi BM59 or even if my select fire came with one installed. Running the steel knitting needle slows down the cyclic rate to a little less than an M14's. I did have trouble getting my select-fire to run with the quick detach off with the knitting needle installed. I ended up leaving the knitting needle out which brought the cylic rate up about 100 rpm. (Now faster than my M14.) Ammo costs so much now, I haven't gone plinking since July 2006. It's been so long since I played with my guns that I can't give you a justified "feel" for cyclic rates, but I felt my M14 was running close to 800 rpm with a bush barrel and Fabian bros. stabilizer(combination brake and booster)

Guidebook for Marines says M14 cyclic rate is 700-750.

Beretta manual says the Ital runs at about 800 rpm.

Doug

 

[TopN]

Doug,

 

Thank you for the info - I remember firing a M-14 on F/A was a real bear to control because the very high rate-of-fire. We were using the "clip-on" M-16 bipods (M-3?) which probably didn't help any.

 

Does the "bush rifle" barrel length slow the rate-of-fire down any, compared to the longer standard barrel?

 

Back to the BM59s - have you had any problems running the hollow spring housing without the "knitting needle" - any damage to recoil spring or damage to the end of the hollow spring housing itself?

 

 

Steve

[winbar]

Doug,

 

Thank you for the info - I remember firing a M-14 on F/A was a real bear to control because the very high rate-of-fire. We were using the "clip-on" M-16 bipods (M-3?) which probably didn't help any.

 

Does the "bush rifle" barrel length slow the rate-of-fire down any, compared to the longer standard barrel?

 

Back to the BM59s - have you had any problems running the hollow spring housing without the "knitting needle" - any damage to recoil spring or damage to the end of the hollow spring housing itself?

 

 

Steve

The BM59 runs fine and about 100 rpm faster without the knitting needle. (No damage noted) As I said, I can't remember if my semi even had one installed. (Does anyone have an SA BM59 to verify? I bought mine for the barrel and disassembled it immediately.) The E model didn't use one, and I think it was develped to slow down the cyclic rate of the models using a tricomp.

The bush barrel on the M14 doesn't change the cyclic rate, but the brakes I have with booster chambers do speed the gun up.

The M14 with all E2 hardware installed still takes a hell of a lot of muscle to control.

Doug

Edited July 22, 2011 by winbar

[TopN]

Doug,

 

All the SA Inc. BM59's I've taken down (only about 4-5) have had the solid 1 piece recoil spring guide. It is my understanding that these 1 piece guides were made for export BM59 Mark 1-4 series rifles. SA Inc. got them when they bought out Beretta's remaining parts stocks. I know Reese only recomended the 1 piece guides for semi-auto BM59's.

 

It would be interesting to know if the Mark 1 & 2 Compensators (the ones that take mod M-1 Bayonets & can't take Grenades) have a "booster chamber". Reese offered those Compensators, and I kick myself for not getting one.

 

Steve

[winbar]

Doug,

 

All the SA Inc. BM59's I've taken down (only about 4-5) have had the solid 1 piece recoil spring guide. It is my understanding that these 1 piece guides were made for export BM59 Mark 1-4 series rifles. SA Inc. got them when they bought out Beretta's remaining parts stocks. I know Reese only recomended the 1 piece guides for semi-auto BM59's.

 

It would be interesting to know if the Mark 1 & 2 Compensators (the ones that take mod M-1 Bayonets & can't take Grenades) have a "booster chamber". Reese offered those Compensators, and I kick myself for not getting one.

 

Steve

The Mark 1 comp does have a booster chamber. (I have one) My semi BM59 came from Davidsons in 2001 in the Springfield Armory box. The story was something like they found some or put some together. It has the hollow spring guide, and I just don't remember if it had a knitting needle or not. As I said, I bought it for the barrel and dropped the parts in with my other spares.

Dan Shea did a review of BM59s in Machine Gun News in Oct 89 and was really impressed with the E model's compensator. I bought an "E" parts kit from Old Sacramento Armory in the spring of 1997. I was so curious about the compensator that I "notched" a garand tanker op rod for the disconnector lever, and installed a .308 tanker barrel on my select fire so I could shoot the "E" compensator. It is very effective. So much so that I used the E compensator port pattern for the brake I made for my BAR, and opened up the corresponding "pepper" holes on my reclaimed quick detach and a spare Ital tricomp. The E model port pattern pushes the gun down and left to " neutralize" the "up and right" of off-hand right handed full-auto shooting.

Doug

[Wotan]

One of my "dumpster-diving" penpals SWAG'ed (SWAG=Scientific Wild-Ass Guess) that the Short Tricomp might have been for the Italian Carabinieri (sort of a cross between State Police, FBI & Army Military Police).

 

TopN

 

Hi, reading this remembered to me that Carabinieri used (still use?) BM59s as anti-riot gas grenade launcher. Maybe the shorter tricomps are for this pourpose.

 

Ciao,

W.