Coonan Reloading Question

[lmjyahoo]

I’ve read 125gr & Win 296 give a good crowd drawing fire-ball from a Coonan Classic. I’ve got the Win 296 & a box of Berry’s 125gr Flat Point. My Lee Modern Reloading book says a starting load of 21gr for the XTP has a velocity of
1881 FPS. My box of Berry’s says 1250 max. I do not want to hurt the gun or myself, but what happens if I push the plated bullet too fast? Other than the Win 296, what other powder will have a good fireball with the Berry’s 125gr?
Thanks in advance for any info.

 

[Aguila Blanca]

From Berry's web site, about that bullet (but they have the same caveat for all their plated bullets):

Don’t exceed the recommended maximum velocities listed. This creates bullet core separation and accuracy issues.

Berry's also cautions against over-crimping, because this can damage the plating and result in core separation.

 

[GarrettJ]

As noted, you won’t hurt your gun pushing Berry’s that hard. Worst case is poor accuracy and maybe some copper deposits in your rifling.

Zero Bullets makes some good, high quality jacketed bullets that are very competitive with Berry’s on a cost basis. That’s what I use in my Desert Eagle.

And yes, Win 296 makes for some excellent fireballs.

 

[Old 454]

I personally would not push a plated bullet that hard.

Check out RMR for some good deal in 38/357 fmj peojectiles.

And yes W296/H110 are good powders for full house rounds

 

[T. O'Heir]

1,024px is too big.
The 21 grain load is out of a 10" barrel(for some daft reason, likely to give impressive velocities Hodgdon tested with one of 'em.) You won't get even close with a shorter barrel. The velocity will be the only difference though. You're not going to hurt your pistol with a Start load.
"...Lee Modern Reloading book..." Lee tests nothing themselves. Their data is usually from the powder makers. That does not mean your manual is no good though. In any case, all manuals are different. They reflect averages of loads tested using the components, firearm/barrel(its length matters) and environmental conditions on the day of the tests.
Berry’s 125 grain Flat Point(.357?) is a plated bullet, not a jacketed like an XTP. Plated bullets use cast bullet data. Drive a plated bullet too fast will leave plating material in your barrel.

 

[Sevens]

I will second the suggestion for Zero 125gr JSP or JHP for the W296 loads and a Coonan Classic. I’m a big fan of Berry’s bullets but not for this role.

To have fun with those Berry’s 125’s and your Coonan Classic, grab a one-pound bottle of Alliant Power Pistol and use the accessory 10-pound spring for hot .38 Special loads. My .38 Special Coonan-specific load runs about 1,050 fps and uses the 10-pound spring.

 

[44 AMP]

My Lee Modern Reloading book says a starting load of 21gr for the XTP has a velocity of
1881 FPS.

Something here is out of wack. First point, XTP is a specific Hornady JACKETED bullet. Other then weight it is in NO WAY the same as a plated bullet. Data for the XTP is NOT correct for any plated bullet and could be dangerous at worst and unsuitable at best.

Next point, if the bullet maker says "do not exceed XXXXfps" the DO NOT EXCEED it. No matter what anybody's reloading manual says.

I have a Coonan Model A. Also have a Desert Eagle .357. The Coonan will handle lead, plated, and jacketed, due to the recoil operation. The DE is jacketed bullets only, due to the gas operation.

PLATED bullets have velocity limits and are not well suited to the full power .357 level needed to work the pistol's action. If you change springs in the Coonan to ones suited for .38+p level loads plated bullets will work and can be run within their limits.

HOWEVER, they aren't a good choice. W296 (magnum primers) and jacketed bullets are better. And, I'd go with the 158gr over the 125, but that's just me.

I don't load to get an impressive fireball. I load for performance, and if I get an impressive fireball (which any slow pistol powder 2400, H110, 296 or AA No.9 will do) that just ...freakin' cool!

and just as a tip, you won't get 1881fps from any 6" or less .357 barrel, no matter what. From a 10" or longer, maybe, from a carbine, yes, but not from any conventional length pistol. (and that is with jacketed, NOT plated bullets. Plated bullets aren't even in consideration for high velocity loads)

 

[pwc]

Doesn't the fireball indicate excess powder to that which is needed from a given length bbl.

Are you shooting for accuracy, to BBQ your target, or for fireworks?

 

[Sevens]

Don’t forget FUN and ENJOYMENT. If you cannot see that as being part of the draw, there will be a disconnect in the discussion.

 

[Dain Bramage]

21g of 296 with 125g XTPs gave great accuracy out of my Coonan, but I was getting FTFs. No such problems with my Alliant 2400 powder load and the same bullet. I noticed that the Hodgdon specified cartridge overall length (COL) of 1.590" was the longest of my Coonan-specific loads. Per the Alliant website, the 2400 load had a COL of 1.580". You wouldn't think ten thousands would make a difference, but it's the only real change. I would be wary about seating the 296 load any deeper.

I've also found that the .38 Spl spring doesn't work with any .357 load I tried. I shoot 125g X-Treme plated bullets with an HS-6 load that functions just fine with the magnum spring. One recommendation straight from Coonan (before they folded) was running the gun wet, with drops of oil on top of the barrel near the muzzle and breech.

Edited to add: Curiously, Hodgdon's 158g XTP COL with 296 is 1.580", which is shorter than the 125g spec. Also, the above 2400 XTP COL I use is based on Alliant's 125g Speer GDHP spec, just to be clear.

 

[libiglou]

A bit off topic but I don't load spicy for this Gun. I use the RMR 135GR TMJ's and AA7 for a functional but accurate load. The biggest reason is that Coonan folded at least for the time being(I have a feeling they will back) so as much fun as this gun is with full power loads if anything breaks your screwed. Plus I hear they are starting to climb up in value.

 

[labnoti]

The biggest fireballs come from powder that is burnt after the bullet leaves the muzzle. The still-burning powder and gas is expelled out the muzzle. To avoid having most of the powder combust while the bullet is still within the barrel, a slow-burning powder that is heavily covered with deterrent is used. 296/H110 is an example of a ball powder with a lot of deterrent. Typically, any powder with a large-mass charge in the appropriate/safe published data for the cartridge can do this given a short-barrel.

So for the Berry's bullet specifically, just find the largest mass charge that won't exceed the velocity limit specified by Berry's.

For other bullets, lower mass bullets leave the muzzle sooner and allow for even larger charges of powder behind them, both of which increase the fire ball. So ideally you'd get something like a 110 grain Barnes TAC-XP. This is a solid-copper bullet that will take very high velocity without separating or fouling in the barrel (but will probably fragment on impact at greater than .38 Special velocities). Work up to a maximum charge of 296, H110, 300 MP or Enforcer or something like that.

 

[44 AMP]

The biggest fireballs come from powder that is burnt after the bullet leaves the muzzle.

True.

The still-burning powder and gas is expelled out the muzzle.

True.

To avoid having most of the powder combust while the bullet is still within the barrel, a slow-burning powder that is heavily covered with deterrent is used

This is nonsense. As written it makes no sense, to me, at any rate.

I think I might know what you are trying to say, but as written I can't be sure and its incorrect as well. Nobody is "trying to AVOID having most of the powder combust while the bullet is still in the barrel" Rather we usually try for the opposite, having most of the powder burn in the barrel.

Powders like 296 are heavily coated with deterrent chemicals to retard their burn rate. NOT so they produce a large flash, but so that the slower burn gives more "push" over the time the bullet is in the barrel.

Look at the load data with short barrels and slow powders. Even though a lot of the powder seems to burn outside the barrel, the part that does burn in the short barrels generally yields higher if not the highest velocities than "faster powders". The downside is there is more than enough unburnt/still burning powder ejected from shorter barrels to give a large flash. Its not the intent, its the unavoidable result with the chemicals used and the length of barrel they burn in. There's no free lunch.

The deterrent coating used in 296 is part of what makes it burn the way it does. That burn rate gives you one size flash in a 4", a different one in a 6", and a much different one in an 18" barrel. The coating used on some powders to produce low flash loads for use in short barrel guns is a different substance and a different subject. I guessing you are confusing the two.

Back to the Coonan, my experience is that you may find you need to run light bullet loads at or near top end levels, in order to provide the recoil needed for consistent operation of the action. The industry standard weight bullet was, and still is the 158gr. Tolerances vary, every gun is an individual, but you may find you need to run light bullets (125gr etc) hot enough to produce the same level of recoil the standard 158s do. (unless you change something in the gun springs, etc.)

Personally, I wouldn't bother with W296 in the .357 Mag Coonan. I would use 2400. Its less sensitive to load density than 296, will give nearly the same velocities and will give you that big fireball you want, from a 6" or shorter barrel.