Officers Model 38 - Inconsistent Velocity Stats???

[TheTinMan]

GENERALLY SPEAKING, if one gun gives wide extreme spreads and large SD'S in comparison to other guns being tested at the same time with the same loads it is caused by ignition problems, ie: IT ain't wailin' 'ell outta the primers enough !!! NOTE: primers are made to work correctly with the proper amount of impact being applied to them. They work even better if you really hit the dickens out of 'em with alacrity. As a matter of fact you can take standard pistol primers and turn 'em into MAG primers with heavy extra heavy firing pin impacts. YOU can also take MAG primers and turn 'em into standard primers with wimpy firing pin impacts.
This is the reason why acrossed the board the fastest guns by FPS produced in order are : RUGER, S&W, COLT,and bringing up the rear always, DAN WESSON.
AND to those who wonder, this is NOT by any guessing but by chronographing hundreds of various sixguns by all those makers by YEST for two different ammunition companies.

I did look carefully at the primers because someone else had suggested inconsistent primer strikes as well. They certainly look like they're getting hit well and consistently. Maybe there's a difference in the shape of the firing pins?

Is there another brand of primer that is more sensitive than CCI? In the service rifle world, we worry about "slam fires" and want the hardest primers available...

Thanks for you all's thoughts and suggestions.

[Zeke38]

I won't argue the Primer issue, try Federals or Winchester. I noticed that the two Smiths that were tested were very short bbls in relation to your OM. Nice group push that 231 up a couple more 10ths of a grain and see what happens with your Colt's.

I like 4.0 of 231 and that bullet in 4" revolvers.

An afterthought, bullet weight will affect crimp and resistance, again I would try a heavier bullet with the idea that the heavier bullet will give a more consistent burn.

[TheTinMan]

Thanks Zeke - I got some 158gr LSWC HP bullets for .357 Magnum and will try them in the .38 Specials as well.

[hanover67]

Your Colt Officer's Model may have a smaller diameter barrel than the S & W's, perhaps .356 rather than .357. Slug your barrels and see. If this is the case, try bullets sized to .357 in the Colt and see if the velocity spread narrows. But, if the target you posted is indicative of the accuracy with existing loads, why not continue to use it?

[hanover67]

Further to my thread of yesterday. I slugged the barrel of my Colt Officer's Model today and the groove diameter is .353, much tighter than I had thought. Also, I read an article by Ken Waters some years ago about inconsistant velocities in the .32-20 handgun cartridge, the cure for which was to trim all cases to the same length and apply a firm crimp so that ingition was more consistant before the bullet left the chamber. Can't hurt to try that to see if it helps.

[TheTinMan]

Further to my thread of yesterday. I slugged the barrel of my Colt Officer's Model today and the groove diameter is .353, much tighter than I had thought. Also, I read an article by Ken Waters some years ago about inconsistant velocities in the .32-20 handgun cartridge, the cure for which was to trim all cases to the same length and apply a firm crimp so that ingition was more consistant before the bullet left the chamber. Can't hurt to try that to see if it helps.

Thanks for your suggestions! I'm going to try Federal primers but hadn't thought about making sure case lengths are consistent. That should make a difference in terms of the crimp consistency.

As far as slugging the barrel goes, it's my understanding that you want bullets sized to be tight in the cylinder throats so that's what I plan on measuring.

Finally, you make a good point about the target. A chronograph is a great tool, but where the pistol puts bullets on paper is what matters - not numbers on a chart. Assuming everything is safe, of course.

[Zeke38]

I have an Officer's Model Target and it shoots fine. My S&W 14-3 won't shoot with it due to better trigger on my 1912 charmer.

Wil Terry good info thanks for sharing on primer crushing. Assume the same goes for rifle cartridges?

[Oyeboten]

Finally, you make a good point about the target. A chronograph is a great tool, but where the pistol puts bullets on paper is what matters - not numbers on a chart. Assuming everything is safe, of course.

Yes...but, once you get farther out than ten yards or whatever, inconsistent FPS will mean you are, at best, shooting a vertical lne of Holes in the Target, and, the farther away the Target is, the worse or greater the vertical spread.

The Chronograph can aid us by alerting us to meaningful inconsistencies of FPS, in order for us to experiment and find ways to rectify it, so that the Bullets will - once the Cartridges are consistent - all strike in the same spot, rather than making a vertical spread.

[Ratzo]

Never believe the stated velocity in a reloading manual.

The cylinder throats and the cylinder to barrel gap could be different, and most likely is on all three revolvers. This difference could bleed off gasses needed to propel the bullet. I compared a Freedom Arms 97 4" against a 5 1/2" 3rd Gen SAA in .45 Colt, and found the velocity higher on the Freedom Arms than the Colt. Only thing I could determine is the tolerances on the FA are much tighter than the Colt. With those mild loads I would only concern myself with the accuracy. Unless you are trying to meet a power factor for competition.

MHO on primers is always use Federal. They have proven to be the most consistant of all I have tried. CCI cups are much heavier than the Federals and light hammer strikes from target guns would not always ignite them. My target load of 3.2 grains of WW231 in my 6" Python would give me 740-760 fps regularly with a 148 grain bullet and a standard primer. Keep in mind that the rule of thumb is 25 fps change in velocity per inch of barrel in a handgun. All things being equal.

[Oyeboten]

Never believe the stated velocity in a reloading manual.

The cylinder throats and the cylinder to barrel gap could be different, and most likely is on all three revolvers. This difference could bleed off gasses needed to propel the bullet. I compared a Freedom Arms 97 4" against a 5 1/2" 3rd Gen SAA in .45 Colt, and found the velocity higher on the Freedom Arms than the Colt. Only thing I could determine is the tolerances on the FA are much tighter than the Colt. With those mild loads I would only concern myself with the accuracy. Unless you are trying to meet a power factor for competition.

Indeed.


If wishing to test Loads and or to test their consistency, one must use the same Revolver to eliminate these variables.


Also, measure the Cylinder Bores and Barrel Bore to see how compatible those are with the Candidate Bullet diameter. If the bullet is a little too small, Blow By, Leading, or poor accuracy may result.


After that, finding the best brand of Brass for the intended Arm and Loading, and, keeping all to the same Brand there-after, and, staying with the same brand of Primer, elected for it's best performance with the arm in question and the Loading in question.

All of it matters, and, if accuracy or accuracy over distance is the goal, it all matters a lot.

MHO on primers is always use Federal. They have proven to be the most consistant of all I have tried. CCI cups are much heavier than the Federals and light hammer strikes from target guns would not always ignite them. My target load of 3.2 grains of WW231 in my 6" Python would give me 740-760 fps regularly with a 148 grain bullet and a standard primer. Keep in mind that the rule of thumb is 25 fps change in velocity per inch of barrel in a handgun. All things being equal.

Good Thread!