Just curious to know if anybody out in TargetTalk world has experimented with different lengths of barrels in the CM84 free pistol.
I'm interested in moving the centre of gravity back more toward the grip and am wondering if shortening the barrel is the right way to go to achieve this. I shoot with the compensator as it improves my ability to call my shots. I've been thinking about reducing the muzzle-heavy effect caused by the compensator by reducing barrel length by an inch or two. Likewise, the idea of reducing the outside diameter of the barrel has also crossed my mind as a way of reducing mass forward of the grip. All of these modifications have to be considered in conjunction with their impact on accuracy and reliability of the pistol.
I'd like to hear any thoughts you might wish to share as a result of your experiences in experimenting with FP barrel lengths. Likewise, if there's a source of supply for shorter barrels or other components like lighter compensators I'd appreciate this input as well.
Anybody Do CM84 Barrel Length Experimentation?
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Mark Briggs
- Posts: 583
- Joined: Mon Mar 01, 2004 8:35 am
- Location: The Frigid North - Ottawa, Canada
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Jim B.
Hi,
I don't have any experience with the Morini FP, but I've shot several examples of the Toz 35 in which the barrel had been shortened from 2 to 3 inches. The effect on balance is very much in line with your stated goal: a shift in the center of gravity away from the muzzle. I could not detect any change in grouping ability, but then again I did not compare from a machine rest. Also, the bullet is out of the barrel sooner, thus aiding follow through. As the muzzle crown is a critical part of barrel performance, it is important that the cutting, squaring and crowning be done right. I think such work, if done right, can even improve some barrels. Find a local gunsmith who has a reputation for such work (smallbore competitive riflesmith, etc.) have the barrel cut incrementally while you wait until the desired balance is achieved, then proceed with the crowning operation, etc. For a few inches, you won't cause any detrimental ballistic effect. Like shaping the grip wood, it is part of fitting the gun to the shooter.
Enjoy, and let us know how it all comes out!
I don't have any experience with the Morini FP, but I've shot several examples of the Toz 35 in which the barrel had been shortened from 2 to 3 inches. The effect on balance is very much in line with your stated goal: a shift in the center of gravity away from the muzzle. I could not detect any change in grouping ability, but then again I did not compare from a machine rest. Also, the bullet is out of the barrel sooner, thus aiding follow through. As the muzzle crown is a critical part of barrel performance, it is important that the cutting, squaring and crowning be done right. I think such work, if done right, can even improve some barrels. Find a local gunsmith who has a reputation for such work (smallbore competitive riflesmith, etc.) have the barrel cut incrementally while you wait until the desired balance is achieved, then proceed with the crowning operation, etc. For a few inches, you won't cause any detrimental ballistic effect. Like shaping the grip wood, it is part of fitting the gun to the shooter.
Enjoy, and let us know how it all comes out!
Barrel Length
Prior to the Sydney Olympics I made two new Barrels for my Morini. one 10", one 14" (factory is approx. 12").
Cut a long development story short, the long barrel was reduced to 10" after the games.
I now shoot a 10" barrel with a compensator and a rear sight extension (similar to the short air pistol). The extension gives me the same sight radius as the normal barrel, but with less forward weight and less windage.
Testing in the machine shows no loss of group size with the short barrel.
I am now hoping it will be very windy in Athens.
Cut a long development story short, the long barrel was reduced to 10" after the games.
I now shoot a 10" barrel with a compensator and a rear sight extension (similar to the short air pistol). The extension gives me the same sight radius as the normal barrel, but with less forward weight and less windage.
Testing in the machine shows no loss of group size with the short barrel.
I am now hoping it will be very windy in Athens.
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Mark Briggs
- Posts: 583
- Joined: Mon Mar 01, 2004 8:35 am
- Location: The Frigid North - Ottawa, Canada
A Couple of Additional Questions...
Thanks to Jim, Rob and David for your most helpful replies. As always, a good reply provokes thought and often begets another question... *grin*
Jim - your point on crowning is well made and well taken. I will certainly pay attention to this detail.
Rob - how much weight do the "longarm whiskers" add to the basic pistol weight? I'm having trouble with my shoulder and after a year of recovery don't want to exacerbate the situation by hefting a huge amount of weight in my pistol. My CM84 weighs in at 1260 grams with compensator, while my Hammerli 150 is almost exactly 100 grams heavier. Both for me are shootable, but I wouldn't want to go over about 1400 grams if avoidable.
David - We've chatted here before about compensators and if I recall correctly you shoot a homemade version much like the Walther comp. Once the pressure is off following the Olympics I'd welcome an opportunity to discuss both the compensator and the shorter barrel length with you in greater detail. I have access to your e-mail address through another Canadian shooter with whom you've chatted at various world cups so will contact you off-line in September, if that's OK with you.
I wasn't sure if you were going to Athens or not and am pleased to hear that you're on your way. Best of luck to you in your pursuit of an Olympic medal. Your performance in the Athens WC Finals was awe-inspiring. Give 'em heck again in Athens!
Cheers,
Mark.[/b]
Jim - your point on crowning is well made and well taken. I will certainly pay attention to this detail.
Rob - how much weight do the "longarm whiskers" add to the basic pistol weight? I'm having trouble with my shoulder and after a year of recovery don't want to exacerbate the situation by hefting a huge amount of weight in my pistol. My CM84 weighs in at 1260 grams with compensator, while my Hammerli 150 is almost exactly 100 grams heavier. Both for me are shootable, but I wouldn't want to go over about 1400 grams if avoidable.
David - We've chatted here before about compensators and if I recall correctly you shoot a homemade version much like the Walther comp. Once the pressure is off following the Olympics I'd welcome an opportunity to discuss both the compensator and the shorter barrel length with you in greater detail. I have access to your e-mail address through another Canadian shooter with whom you've chatted at various world cups so will contact you off-line in September, if that's OK with you.
I wasn't sure if you were going to Athens or not and am pleased to hear that you're on your way. Best of luck to you in your pursuit of an Olympic medal. Your performance in the Athens WC Finals was awe-inspiring. Give 'em heck again in Athens!
Cheers,
Mark.[/b]
84e
The UK 84e is just over 300mm for legal reasons and the rods at the back give an overall length of just over 600mm. The rods are very light but the "T" bar that attaches them to the pistol bump overall weight 1.4kg. The actual weights on the rear rods are only a few g and can move along the rod, they do enable fine-tune of the balance. Yes it is heavy.
I also use the compensator but with the rear rods, the balance for me is very nice.
Early Morini FP's had rods front and rear for fine-tuning. As you do not have the legal issues we have in the UK you may like to deploy just the rods with a light weight fixing for the same result. The UK "T" bar block is just forward of trigger so you have a lot to play with before the overall weight bumps up.
Good luck to David in Athens. I do recall he may produce some custom compensators afterwards (or maybe some plans?).
I also use the compensator but with the rear rods, the balance for me is very nice.
Early Morini FP's had rods front and rear for fine-tuning. As you do not have the legal issues we have in the UK you may like to deploy just the rods with a light weight fixing for the same result. The UK "T" bar block is just forward of trigger so you have a lot to play with before the overall weight bumps up.
Good luck to David in Athens. I do recall he may produce some custom compensators afterwards (or maybe some plans?).