45 LC velocity low. lots of questions.
Have a Colt SAA in 45, Chrono'ing it as well as shooting it and feeling recoil I notice real low velocities compared to "the books". Now, while I realize the books are just a guideline, still my velocities are REALLY low. Using trail boss, WW231, and IMR 4227. Velocities are about 150-200 fps low. As an example, my imr4227 books at 890 but I get 700. Groove is .452, throats are .455. Tried .452 and .454 bullets in WW alloy and 20:1 alloy and made an expander bigger than factory so the case does not swage down the bullet. Now, switching to magnum primers I get some velocity back (book = 890, my chrono gives 770). Bullet size had almost zero effect on velocities. Chrono was checked with other guns of known velocity. Was going to use trail boss for low V plinking loads, and either 231 or 4227 for "full house loads" but WW231 gave me my first indication of case sensitivity. Just shooting the gun gave me velocities of around 700 FPS. Settling the powder by the primer before each shot gave me a velocity of 825 fps! This only happened with WW231. thus I cant use this powder as I am not going to mess around with that for each shot. So....how do i get velocity higher to what it should be? I wish my throats were smaller but I dont believe I am getting blow by (soft and hard bullets gave the same V, 452 and 454 bullets gave the same V. I should add my 422 bullets actaully came out .453 and the .454 came out around .455). the only thing that helped was magnum primers for both 231 and 4227. Would a tighter crimp help?? Maybe I should expand the cases with the regular expander so it crimps the bullet tighter, altho this did nothing using regular primers and .452 bullets.
Finally, another fly in the ointment. The gun came with a Wolf spring kit in it. This gives light primer hits and in fact with magnum primers I got a misfire. I plan on installing factory springs (where can in buy these...do i have to go to Colt?). What is typically changed in a wolf spring kit? Mainspring? Trigger spring? Would this lead to low Velocity? I think it may lead to poor accuracy (altho some fo the groups are really tight!!) but would it lead to consistant low velocity?
Thanks to all
Finally, another fly in the ointment. The gun came with a Wolf spring kit in it. This gives light primer hits and in fact with magnum primers I got a misfire. I plan on installing factory springs (where can in buy these...do i have to go to Colt?). What is typically changed in a wolf spring kit? Mainspring? Trigger spring? Would this lead to low Velocity? I think it may lead to poor accuracy (altho some fo the groups are really tight!!) but would it lead to consistant low velocity?
Thanks to all
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If your getting tight groups I wouldn't worry about. The SAA with it's fixed sights wasn't meant to be a target gun. It was designed for relatively low velocity Black Powder loads in the 19th Century. The only way your going to get higher velocities is with a case full of slow burning powder ignited by a mag primer with a heavy crimp. You don't want to go their with a SAA. If you want to experiment with those kind of loads buy a Blackhawk or a Contender. 0 -
Dad has a blackhawk in 45LC, but the same loads in my Colt are anemic. I may try what you suggest with a heavier crimp. All load data I use is listed for the Colt SAA and clones...dont worry..I am not trying to make a blackhawk out of my Colt. remember I dont want "higher velocity", I am after velocity near what the books list for the given weight and load. 0 -
I have had problems in the past loading high capacity cases, (45 LC & 10MM) with less then maximum charges of medium and slow burning powders and relatively light bullets.
When using the heaviest bullets available in 10MM, (200 & 220) and fast burning powder, the problem went away. Since the interior of the 45LC case is so large, your going to have even more of a problem.
Use the heaviest bullets you can obtain for the 45 LC with a tight crimp. The interior case dimensions are so large you can actually hear and feel the difference, because the powder doesn't burn uniformly between shots, as you have found out when chroning the 231 loads.0 -
Have you chronographed your loads varying from UP and DOWN ?
There is a phenomenon with the 45LC regarding the position of the gun prior to firing which affects the position of the powder. If you actually shake the gun in an up or down position before firing each round and then gently bring the gun to the horizontal and fire, you may notice a difference. For example, average velocity using the UP position has been noted to be close to 180 FPS faster than the exact same load fired from the DOWN position.
Might be worth a try although if accuracy is acceptable I don't think I would worry about it.
Dan R0 -
Well sir, the first thing that comes to my mind is barrel/cylinder gap. How wide is the space between the barrel and cylinder? Does the cylinder slide forward or backward on the cylinder pin? My Dan Wesson's show the same symptom as you describe if I don't check gap when I change barrels.[;)][;)][;)][;)]Eddie 0 -
quote:Originally posted by elubsme
Well sir, the first thing that comes to my mind is barrel/cylinder gap. How wide is the space between the barrel and cylinder? Does the cylinder slide forward or backward on the cylinder pin? My Dan Wesson's show the same symptom as you describe if I don't check gap when I change barrels.[;)][;)][;)][;)]Eddie
I agree with this bit, and it was actually my first thought too.
Most of the above explications are true, but they don't explain consistently low velocities. A large barrel-cylinder gap could explain consistently low velocities.
If the cylinder gap were too large, you should see:
a. The SAME loads giving NORMAL velocities in a SECOND gun, and
b. Ordinary loads also giving lower-than-normal velocities from this gun.
Since you say your dad's Blackhawk shoots the same loads faster, this could be your explanation.
I think a weak crimp might explain lower than expected velocities in certain loads, BUT I don't think putting weak-crimped loads in a different gun would correct the problem.
A weak mainspring might explain primer misfires, but it can't explain lower than usual velocities. Either the primer goes off or it doesn't. If it goes off, it goes off, and it shouldn't affect velocities based on how hard it was hit.
In terms of a little bit of powder in a big case, that sort of thing usually leads to INCONSISTENT velocities, not necessarily low ones.
This is the reason why old-fashioned target shooters would point the barrel of their gun upwards and settle it downwards before every shot. That way the powder settles consistently within the cartridge for every shot, leading to more consistent velocities and therefore better accuracy.
If this were the problem, you might expect to see a wide SPREAD of velocities (or to put it statistically, a high standard deviation), not low velocities.
And again, if this were the case (pun not intended), you would expect to see the same problem using these loads in other guns.0 -
Was the revolver you used in the test the same barrel length? Same bore diameter? Same diameter of the six chambers?
I use large volume powder (Unique) in my .45 revolvers. 255gr bullets. Heavy crimp on the ogive. Best, Joe0 -
My vote on most likely is +1 on Barrel to Cylinder Gap. 0 -
Compare your barrel length with that in the printed material, and switch to Unique powder. Also, 4227 is more suited for rifles, as it is a slow burning powder. If your pistol has a short barrel, the powder may just be burning outside the barrel, where it has no effect on the bullet. Seems you need a powder more suited to pistols. BT 0 -
You don't indicate what reference you are using for "book" values. Take a close look at your book and see if it tells what gun was used to test their loads. It is not uncommon for the data listed in a book to be developed using a special pressure test barrel, possibly with a longer barrel than your gun, and most likely with no cylinder gap. 0 -
The last poster had it, look to see if it was a pressure barrel, or a gun like the one you have. I see velocities listed all the time with 7.5" pressure barrels, and if your SAA is a 4 3/4", then you're obviously going to be low. My old Colt had a large B/C gap as well, which bled off a lot of velocity.
IMO trail boss and unique, with a proper crimp, are a great way to go with lighter loads in this big case.0
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