January 19, 2001, 06:17
I have a quantity of tracer bullets bought from both Widener's and Hi-Tech. The bullets bought at Wideners were advertised as M25 for .30-06; the ones bought at Hi-Tech were advertised as M62 for .308. Both lots are mixed types that appear the same, meaning they are made up of equal portions of two different bullets. One type has a single cannelure with the tracer compound visible at the base of the bullet. The other type has 2 cannelures with an inverted copper cup covering the tracer compound. My guess is that the single cannelure is for proper seating with '06 whereas the other may be used for both. Any RKI's out there want to set me straight??
Also, they are 145 gr bullets. Do I just use my proven loads for 150 FMJ, or do I have to start over with work-ups??
January 20, 2001, 02:21
Working up from scratch is the safest thing to do if you change any component of your developed and tested load. I won't tell you to NOT do it. There are, however, some shortcuts that may help speed things up.
Say you want to try a different bullet of a close but different weight, like going from your 150 grain bullet to your 145 grain bullet.
Generally, a lighter bullet will generate less pressure than a heavier bullet, all other things being equal. The kicker is that all other things are NEVER equal!
Unless the two bullets are from the same manufacturer and were developed by the manufacturer for the same purpose, the bullets may have a lot more differences than just the 5 grains of weight. They may have different core alloys, that will affect hardness. They may have different bullet jacket alloys, one being 'slippery-er' than the other. They may have different amounts of bearing surface (the 'flat' sides of the bullet, the portion of a bullet that is actually in contact with the barrel when it is being fired). So, two different bullets may be similar in weight but be very different in a lot of other ways that will affect the pressure that the finished load generates.
Again, I won't say to NOT work up your load all over again when changing any component. I will say, there are some shortcuts that may help.
Say you are using 45 grains of IMR-1234 powder with your 150 grain bullet load now. You want to try the 145 grain bullet with the same load.
Reduce your normal load's powder charge by 10%, or by 4.5 grains, to 40.5 grains. Load three rounds with 40.5 grains and the 145 grain bullet. Then load three rounds with 42.0 grains, three more with 43.5 grains, three more with 44.0 grains, three more with 44.5 grains, then three more with 45.0 grains. Keep the loads separate and label them (I use a felt tip pen and write the charge weight on the side of each cartridge).
Take your loads and rifle to the range. Put up a clean target. Fire the 40.5 grain loads. Take your time, shoot for accuracy. Look at the brass, pay attention to how they fired and extracted and ejected and compare their behavior to your standard load. Look at your three round group and mark it. Then fire the next warmer (42.0 grains) load. Repeat the check. Work your way back up to the 45.0 grain weight, three rounds at a time.
You should see any signs of excess pressure before you get to the heaviest load, if there are going to be any. If you do see signs any load is hotter than the regular load (45.0 grains of powder, 150 grain bullet), it is time to stop and figure out why.
You have now only loaded and fired 18 new rounds. How did they perform?
I would guess that you will find out that the 145 grain bullets work pretty much like the 150 grain bullets with the same powder charge, if they are both FMJ ball-type bullets, but this is only a guess. It only costs 18 trial loads to find out. This is cheap insurance.
While working through the different powder charges, you may find a charge level that groups notably better than the other charge weights. Three round groups mean nothing, statistically, but it may be worth investigating, especially if the groups, taken together, indicate a trend, like, say, the 40.5 grain group is 1" at 100 yards, the 42.0 grain group is 1.25", the 43.5 grain group is 1.5", the 44.0 grain group is 2", the 44.5 grain group is 3.5", etc. It may be worthwhile to go back, reload more batches of ammo at different charge weights and shoot more groups, but of 5 or 10 rounds each. You might find out something useful, like the more mild load is a lot more accurate, or the hotter load is more accurate. Or, maybe not.
I once had a great hunting load for deer in my Remington 700 .30-06. I had a 150 grain Sierra boat tail spitzer over a stiff charge of IMR-4350 that shot 1" to 1.5" inch, five shot groups at 100 yards all day, with a 4x scope. I got a great deal on another brand of 150 grain bullet made in a Scandahoovian country. I figured that the same bullet weight would shoot the same way, and loaded up 200 rounds of my old load with the new bullet. I went to the range, and the first shot was a shock- loud, sharp, and the bolt was REALLY hard to lift. The fired case's primer had a raised ring around the firing pin's indentation, but was EXTREMELY flat other than that. I could see where the cartridge case's brass had started to flow into the ejector plunger hole in the bolt face. I fired a second round, and nearly had to beat the bolt open with a plastic mallet.
While my original load with the Sierra bullet was pretty warm, I had worked up to it carefully IN THAT RIFLE, and while warm it was safe. The new load with the Scandahoovian bullet was way over-pressure.
I may have not damaged my rifle with those two rounds, but I then had 198 rounds of unusable ammo to pull the bullets from, one at a time, with an inertia hammer-type bullet puller.
Try the abbreviated work-up procedure outlined above, at least, if you want to try a new bullet.
A lot of highpower rifle shooters will work up their load all over again when changing even powder lots from the same manufacturer. Tedious, maybe, but they buy their components in large enough quantities to load at least 1,000 rounds at a time from the same lot of powder, brass, bullet and primer. They also don't bend their rifles.
Man, am I long-winded, but I sure don't want you picking metal fragments from your face.
January 20, 2001, 07:10
buff, your the man.well said and to the point.been reloading for 28 years and helped alot of friends get started.your post should be read by all.
January 21, 2001, 01:39
Your nickname...a philanthropist once let me shoot a 50 round magazine from his pre-WWII Thompson. Gawd, I loved that gun!
If Ed McMahon and the Prize Patrol ever bring their van to my house, I am buying me a Chicago Typewriter and a violin case!
You don't perchance have one of the 45 caliber little steel lovelies, do you?
January 21, 2001, 23:07
Sign in my hands at the streetcorner by your house:
"WILL WORK FOR THOMPSON"
January 22, 2001, 08:31
Thanks Buff, 'preciate it. This is why I love this board so much.
Any comment on the two types of bullet??
January 22, 2001, 14:14
I've never loaded tracer bullets before.
Let us know how what you try works out, for good or bad!
vBulletin® v3.8.7, Copyright ©2000-2013, vBulletin Solutions, Inc.