1911Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
149 Posts
Discussion Starter · #1 · (Edited)
I am working up some 45 super loads for use in my 625-2. Goal is to achive 270pf for the 'norwegian major magnum class' (min 210gr bullet and 270 power factor). I used a 1911 with barsto barrel (grooves 0.005") and a 225 gr self cast bullet, stopping at 1230 fps (12.2 gr vv n105 and 1.275" OAL). This is a accurate and stout load, showing no overpressure signs. When using the load in the 625-2 accuracy goes down drain, giving occational keyholing. When meassuring grooves they show up beeing just 0.003". I suspect this is causing nonstabilized bullets. Q #1 : are 0.003" grooves standard for S&W? Q #2 : will harder bullets (more antimon) cure problem, or must I go ordinary jacketed bullets?
 

·
Registered
Joined
·
22,176 Posts
Postage on bullets from Pennsylvania to Norway would be kind of steep.

I don't know S&W's present rifling specification, but the .45s used to be considered to have shallow rifling for jacketed bullets.

You could either add antimony or try heat treating your present alloy. Just dropping bullets right out of the mold into water will harden many alloys as long as there is some antimony and a trace of arsenic. Be careful not to splash water into the mold or lead pot.

Bullets can also be heat treated in a kitchen oven. Test to determine the maximum oven temperature that will not deform the bullets. Then heat them up and quench in water.
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #4 ·
Thank's for input! Since I am very cost aware, I will go the cast lane first. Have ordered LEE 2-cavity 255 gr molds which cost the same as 100 jacketed bullets. I will also add more lino to my wheel weights and see if I can get hands on some tin. I guess this is more in line with Chuck Tylor's advertised loads for 25's and 625's with 45 auto rim cases (255gr at 1100 fps). My 625-2 (m of 1988!) is in very good shape, I have even set back and recrowned barrel. Gun is primarily for target (pf 150) and IPSF (pf 175), I doubt I will shoot more than 500-1000 rounds/year with theese high end loads (pf 270).
 

·
Registered
Joined
·
1,096 Posts
Sounds to me like the bullets are getting blow by and not gripping the rifling. All .45 barrels have shallow grooves in a handgun. Using .45 Super cases, what data are you using for cast bullets? I haven't seen any myself as far as data goes. If you want a heavy .45 bullet in a .45 ACP case, try using data for Unique.
 

·
Registered
Joined
·
15,317 Posts
DATA

255g LSWC-GC, 7.0g Herco, WLP, 45AR case, 929fps.
8.0g = 1000fps, 13.0g 2400 = 1100fps.
 

·
Registered
Joined
·
1,096 Posts
I'm confused, are you guys talking about loading .45 Super with .45 Super cases or are you talking about hot .45 ACP and .45 Auto-Rim for use in the 625?
 

·
Registered
Joined
·
69 Posts
10mmfan
Start by checking the throat diameter of the cylinders. Revolvers from different manufacturers at different times change. May have to adjust sizing diameter of bullets for the revolver, based on throat diminsions. Sounds like you may have one with unusually large throat diameters. With a revolver, you size according to throat diameter, ie: if throats are .454", then size that instead of .451 or .452, even though that may be the bore diameter.
(Aren't ya'll METRIC ???)
Just a thought -as I'm in constant pursuit of ultra-accurate .38spl loads, and load for 6 different revolvers, currently. Each has it's own "personality" and preferences for bullets, powder, ect. With cast bullets, diameters for "match" loads go from .356 to .360", and some (2) prefer swagged HB-WC, other 4 do better with Cast WC or SWC.

Barrels are another issue all together !!!!
Check for forcing cone condition first. Then if everything is "OK", then consider recutting it to match bullet type. If you're using a jacketed bullet, the factory 17degree is ok. If using a Cast SWC or other design, an 11degree is preferable, and some have found a very gradual 5degree is preferable (ie: Ruger "factory" diminision. Also, check condition of muzzle crown. Re-crown muzzle with "recessed" 79degree crown (90deg. minus- 11deg) match type crown.

I've seen a "LOT" of keyholed bullet holes in my 50yd revolver targets shooting wadcutters !

As you can see, the REVOLVER is a very different "animal" than the 1911 !!!

Edited to add:
I went back and re-read your reply and noted where you had "set back the barrel". Have you recut the forcing cone too ? If it is too shallow (not recut to sufficient depth) it'll cause the Key-holing.
Brownells sells the cutters and gauges for a very reasonable cost. I've found the 11deg cutters to cut equal or better forcing cones using hand tool and bushings, than using lathe. (Lathe-I have had to have gunsmiths do this for me- don't have one or know how to use one------Yet....)
What is your barrel to Cylinder gap? Should be .0025" min. to .006" (my tolerances, others may disagree- S&W will say something like .012"max before they'll "repair" it) My Performance Center re-cylindered M14's came home with .0025-.004"" gaps
Is it face of barrel "really square" ?


Hope this info helps !!
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #9 ·
GooseGestapo, cylinder troat is .452 (I have 'converted'), cylinder cap is set to .005 (was .010), cone is set to 11 deg's (that is 5.5 deg off centerline) in lathe, muzzle set to 11 deg's off centerline. My main concerne is riefling depth that is .003 (as is my m 67 s8 sp), whereas my 1911 barrels ar .005.
 

·
Registered
Joined
·
15,317 Posts
ACTUAL

Gotta check case capacity between 45 ACP and 45 AR, because you might be suprised if you don't.
 

·
Registered
Joined
·
69 Posts
10mmfan;
I doubt that groove depth is the issue. Try going back and lapping the forcing cone.

Sounds also if you don't have a "Pinned" barrel that you may have a "Tight spot" where the barrel is threaded into the frame.

I know one "high master" PPC competitor who got a MIM M14 "K-38 heavy barrel"(one with the "frame mounted firing pin) that won't shoot "wuff a hoot" (to quote him), because upon air-guaging the barrel -it has about a .003"-.005" constriction where it is "skewoze" down from screwing it into the frame and torqueing into alignment. The lead bullets are getting squeezed down and causing the bullets to be undersize in the rest of the barrel. Accuracy, if you can call it that, is over 6" at 25yds.
I had to have my M14 of 1996 vintage "recylindered" by Perf Ctr. (under warranty at least), but now it shoots fantastic !! (two 2nd place finishes at Nationals so far). Cylinder had one chamber that had helical reamer marks in the throat that would lead up badley and cause "key hole" flyers, but was intermittant.

Check your barrel !!

If that is the case, and you haven't done too many modifications, S&W might replace the barrel under warranty. But, shipping and processing from Norway might still be cost prohibitive.

It might just be cheaper/easier to get a NEW barrel from Brownells, or get a USED one from GUN PARTS CORP.
 

·
Registered
Joined
·
58 Posts
I too thought about possible choke in the thread area. Slugging the barrel would show if this condition exists, or if maybe another zone down the bore would be out of spec..
Should you find something un-kosher with the internal dimension, short of having the barrel replaced by S&W, maybe you could try firelapping the bore?-I have no experience with this process myself, but after all I've read about it, it seems to be a good alternative if properly done.
Firelapping is discussed in depth over at the Beartooth forum, you can get all the necessary supplies and support at Beartooth's too.

I bought a S&W686 with the new rifling profile in 2000, the rifling was completely out of center, 1" near the muzzle the rifling groves where very shallow on one side compared with the opposite side, S&W told me this would have no influence on accuracy and wouldn't be a reason for replacing the barrel; I sold the gun.

http://www.beartoothbullets.com

Quickloader
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #13 ·
GooseGestapo, Quickloader.
Will slug barrel. Have cast some 255 gr's today which will be loaded and shoot tomorrow. My 625-2 is of the unpinned sort. I'm familiar with lapping and will proceede with slugg-lapping (firelapping is a mess, the compound is hard to keep off brass and dies) if thight spot is detected. I'll keep you posted.
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #14 ·
Tight spot!
When slugging barrel a tight spot was detected approx 1" from back end. Very careful inspection gave visual confirmation. Slug lapped with 220, 320 and 600 grit, ca 15-20 passes each. Lapping increased slug from .4505/.4510 to .4515 giving even recistance all the way. Forcing cone seems to bee fine at .470" tapering down to .451" at 5.5 deg. It is a bit rough from turning tool, will make brass lap later.
Shooting.
Have cast 255gr's RNFP at .452 from 50% WW and 50% lino. Am building loads very conservativly with VV n105. Too conservativly, 9.6 gr's with OAL 1.255" giving just 675 fps, a far cry from my 1080 fps goal. Accuracy was very good. Must decrease OAL to 1.225/1.230" to cure chambering problems. Have loaded 10 each 10.0, 10.4, 10.8, 11.0 and 11.2 gr's to check out during weekend.
 

·
Registered
Joined
·
149 Posts
Discussion Starter · #16 ·
The lapping was done with the 255 gr bullets rolled between 2 pieces of steel to make lapping compound stick then inserted and carefully centerd from muzzle end. Then driven trough barrel with mild steel bar wrapped at intervalls with tape. Bullets retrieved from cylinder end, recoated, carefully centered to make lands correspond with imprint in bullet. Used 3-4 bullets for the 50-60 passes.
The final test was todays shooting : velocity from 900 fps (10.0 gr n105 OAL 1.230") to 1067 fps (11.2 gr n105 OAL 1.230) giving PF 272. No alarming preassure signs. Cases expand to .476" (well forward of casehead) in the .480" chamber, no hint of sticky extraction. No leading in forcing cone, slight leading at last 2" to muzzle (which, I think, correspond to high preassure). I will stick with this load, except form setting OAL to 1.225" (these are stubby FP bullets made for 45 colt). I did no accuracy testing, shooting offhand at 15 m DA gave 2-3" groups. There was no indication of unsabilized bullets. So, finally, I think I got what I wanted : 45 super brass, home cast bullets giving 270 PF in S&W 625-2 in a safe manner.
 
1 - 16 of 16 Posts
Top