Primer question...

[sandspider500]

From handloader 279, I think a western powder ballistician tested some enforcer powder loads for some Ruger only 45 colt loads using the same powder charge and bullet, then switched primers. Enforcer in a 45 colt seems to be a bit sensitive.

Not sure if you can see that. It's a 310gr bullet loaded with 21gr of enforcer shot from a 7 1/4" non-vented test barrel, these loads are only for large framed rugers or equivalent.

CCI 350 primers=35,950 psi
Remington 2 1/2=23,990 psi
Winchester LP=22,490 psi
Federal 155=27,870

That's quite a difference in pressure just by switching the primer. I think all of the 45 colt "Ruger" loads from western powder 8 use Remington primers for the data. Pretty interesting.

 

[GasGuzzler]

With enough searching, there can almost always be an exception found.

 

[contender]

True enough GasGuzzler.

I appreciate sandspider500 posting this chart.

I may have to look up that article,, to see all the test perimeters. The chart above is very interesting. But as with any test,, it has to be as identical as possible with only one variable to get truer results.
Examples;
Cases. Were they trimmed to exact dimensions, weighed to be the exact same weight, to be as identical as possible.
Powder. Was it individually weighed for each loading. All the same lot number?
Bullets. Were they all individually weighed, measured etc to be identical?
Loading. Were they all loaded at the same time, under strict conditions, using the same equipment?
Primers. Were each brand weighed to get identical weights? Were the all seated AND mic'ed to check seating depth?

How many test rounds of each one were used?
Was the test tried 2-3 more times using identical settings?
Did they try & change primer lot numbers & re-test?
Did they try & change powder lot numbers & re-test?
Was it done in a universal receiver,, or an actual firearm?
Was the gun or receiver cleaned after EACH shot?

My point to this is there are MANY variables,, and most often,, it's not only very hard to be as identical as you can, but time consuming, and expensive.

I find it very interesting that the other 3 brands were very close together,, while just one was noticeable different. It would cause me to want to truly find out why.

 

[sandspider500]

I think it has to do with the amount of aluminum powder or whatever is used in the primer compound. If different primers were loaded into an empty case, so no bullet, no powder and fired from a 5" test barrel and a video or pictures were taken you would see a difference is obvious. So with some cartridges and powder combinations, you would have a difference as the above example I gave. Some cartridge and powder combinations will have little go no difference.

Here's another example, from Larry Gibson @castboolits,

"From a test I conducted sometime back with the 44 Magnum having primer pockets reamed for LR primers.

RCBS 44-250-K cast of WWs + 2 %tin with a BHN of 16, sized .430 and lubed with Javelina
WW Super 44 Magnum cases (new) with primer pockets reamed for LR primers
WW Super 44 Magnum cases (new) with standard primer pockets with control loads
OAL; 1.711"
Powders; Alliant 2400 (21 gr) & H110 (23 gr)
Results listed as; primer/average velocity (fps)/SD/ES/average PSI (M43)/SD/ES

H110 load;
Control load;
WLP/1400/24/78/21,700/1,200/3,600

LR primer loads;
Rem 9 1/2/1466/47/112/25,200/3,500/8,500
CCI 200/1390/49/141/22,100/1,500/4,200
CCI #34/1507/35/107/28,300/3,000/9,000
WLR/1506/26/85/28,500/2,300/6,000
Fed 215/1544/12/36/31,600/1,500/4,100

Here we see all the psi's within SAAMI proscribed MAP. We find the control load with WLP primers to be relatively mild. The hotter Fed 215 magnum LR primer produced the most consistent internal ballistics and the highest psi with the highest velocity with H110. No pressure problems observed with using the LR primers in this load with H110 powder.

Alliant 2400 load;
Control load;
Fed 150/1542/18/51/30,800/1,000/2,700

LR primer loads;
Rem 9 1/2/1603/13/37/34,700/500/1,200
CCI 200/1589/20/46/33,000/1,800/5,000
CCI #34/1634/10/27/37,900/1,900/5,500
WLR/1633/8/22/37,600/1,000/2,600
Fed 215/1641/13/29/41,200/1,900/4,100

Here we see some LR primers (the "soft" 9 ½ & 200) are OK with this load keeping the psi under the SAAMI MAP/. However, when magnum level LR primers are used we see the psi going Over the MAP and the Fed 215 psi going over the MPSM. Note the very good internal ballistics with this load of 2400 with all the primers tested. Obviously, this load is burning very efficiently in the 30K to 41K psi range."


So, a cartridge like a 9mm or 45 ACP, you may not see a difference through your chronograph or if you had pressure test equipment, no matter what primer you use. Even a larger case like a 45 colt or 44 magnum loaded with a faster powder, or even a certain slow powder, no difference.

 

[gjgalligan]

I found that a chronograph is my most valuable reloading tool after a good powder scale. One can learn many important and valuable things by use of the chronograph.

I'm a rookie at reloading, only started about 12 years ago. When I reload I am looking for reliability of ignition, point of impact, & grouping. If loading semi-auto auto I also look for proper cycling in the firearm.
I have never used a chronograph as I see no need to know the speed if my concerns are met.
What am I missing? I have an open mind.

 

[Pál_K]

I'm a rookie at reloading, only started about 12 years ago. When I reload I am looking for reliability of ignition, point of impact, & grouping. If loading semi-auto auto I also look for proper cycling in the firearm.
I have never used a chronograph as I see no need to know the speed if my concerns are met.
What am I missing? I have an open mind.

If you're using a steady rest to check your groups, that may be all you need.

But one valuable thing would be knowing the spread of velocities from, for example, 10 rounds. If the spread is 150fps from lowest to highest velocity, you're not likely to get a very good group from that load. If the spread is 25fps and you're not getting a good group, that would indicate your load is very good but perhaps some other factor than your powder and load is opening up your groups.

 

[contender]

A chronograph gives you info that you can use to assist in developing safe loads,, and efficient loads. Plus,, if you happen to want to shoot USPSA competition,, you'll need to know the velocities so you can make your power factor.

The loading manuals give you an APPROXIMATE velocity of a given combo using the very same components as they used to develop them. Only by testing will you actually see what you get in your gun(s).

Reliable ignition is important,, but that can depend upon the primers OR the gun. Point of impact is very important because you you want accurate ammo. And grouping is a part of accuracy so yes,, it too is important.

Knowing what your ammo is actually clocking at can assist in accuracy, efficiency, and SAFETY! When you chrono ammo, and get an average,, you can compare it to the safe levels in the manuals. And the Standard Deviation can show you if your load is efficient,, and that too is an aid towards accuracy.

Next,, many folks are now using suppressors,, so to get a sub-sonic load a chrono can show you exactly what you are getting to be sub-sonic.

I got my first chrono decades ago,, and it expanded my knowledge of just what my ammo was doing,, and I wasn't "guessing" about it any longer.