I was thinking about loading some up, when it was pointed out to me that loads under minimum have been known to produce pressure spikes.

While that's been widely reported, last time I checked, no one could reproduce this in a lab.

Also, we have a model for light loads in large cases: the 45-70, for one, where you can load WAY down from case capacity with smokeless powder.

So, is it a problem to produce such loads?

Loads have been known to spike and even blow up some guns with very slow burning powders with small charges, but with fast to medium burning powders and a filer, I use Dacron or those foam plugs from Jeffs Outfitters, you won't have any problems at all..I used to shoot them all the time, but have not for a number of years now. About the same as using lead bullets in your big game rifle.

I think I have the solution in Trail Boss powder.

Speer #12 shows SR 4759 in .300 Wby over a variety of bullet weights. Most are shown at 2000 fps. I've used this powder a lot in reduced loads and I've had no issues.

Trail Boss is meant to be shot in a specific PRESSURE range. If you drop down very far it is not appropriate (per Hodgdon).

Blue Dot seems to be a lot easier to work with, as it seems that so long as you stay below the high-end on pressure then you can go downward as far as you want. I think that large capacity magnums might be a little squirrly with really reduced loads so would be careful there.

Pressure spikes aren't the only problem with subsonic loads. Sometimes during load development you can stick one in the bore. There is a lot of info available on this if you read about the .300 Whisper.

I loaded some Trail Boss, 11 gr. It shot fine, not quite as quiet as I wanted, but about like a CB cap. Used 170 gr. flat point bullets.

I disagree about the use of Trail Boss, although you will obtain average results.

Here is where you need to be:

http://www.gmdr.com/lever/lowveldata.htm

On the left side under 300 Win Mag click on the 170gr FN data tab.
Most people use powders far too slow for sub sonic shooting and the have position problems which leads to large extreme spreads and "poor" accuracy.

Greg Mushials data is tested. safe and reliable.

Be sure to read the context pape at the top of the list of cartridges

I would look at using cast bullets and unique for such loads. Yes, you'll have to be careful as the charge weights will be well under 1/2 case full. But you should achieve decent accuracy, mild recoil and mild report.

The pressure spikes you are likely thinking of are referred to as Secondary Explosion Effect (SEE) you can find info via google. My understaning is that the primer and initial burn of powder push the bullet into the rifling, the bullet comes to a stop, the bore is obstructed, the powder finally gets going, and kablooey.

I've never read of a problem with small charges of faster powders, it's the reduced slow powders that cause the problems as the slower powders are tougher to get lit off when reduced.

And you're not going to get truly quiet unless you use a supressor. The only way I know to get quiet and decent performance sans supressor is a small case, like a 45 acp, small charge of fast powder, and a heavy for caliber cast bullet. The expansion ratio will be such that pressure will really drop by the time the bullet leaves the barrel. But with a large case and small bore, you need a can to quiet it down.

I have a silencer. Which is why I'm going subsonic. Not looking for much accuracy, just a kind of a hobby.

I can't imagine it getting any quieter than a CB cap...

Even with the can the problem seems to be the primer "snap."

With very fast powders you will find the accuracy and reasonable quiet you are looking for.
No need for gas checks, the gc bullets shoot fine without it. Shoot them unsized and tumble lubed and save yourself a lot of "fuss and muss."

Some powders are very position sensitive. Trying Accurate 9 in my 30-30, I had a large difference in MV with the powder at the front of the case vs. the rear. Other powders do not have this problem. TiteGroup and 5744 are two that I have tested that do not have this problem, so far as I can tell.

Hodgdon's instructions for Trail Boss are to mark a case with where the base of the bullet will be, fill the case to there, and weigh the powder. That is a safe maximum load. Multiply this weight by .7, and you have a safe minimum load. Since your case is "reasonably" full, you should not have the position sensitivity problem.

In my 30-30 it only takes 12 grains of Trail Boss to fill the case. A jar of TB is only 9 ounces, and that is all that will fit in the jar.

Brownell showed a huge increase in pressure variability below about 30 KPSI in the 30-06. The scary thing is that he was using 4064 or 3031 if I remember correctly. The SEE problem is well known with 4831, but I suspect it is not unique to really slow burning powders.

Brownell did some pretty interesting work in this area that does support the existence of SEE. He shows pressure traces that literally have sharp, tall spikes riding on them.

I'm not set up to cast .30 caliber bullets. And I don't know if the can is friendly toward them. The only bullet mould I have in 30 caliber is on an Ideal Tool from long ago. It's for a 30-30. A neat tool, the Ideal.

As for it sounding like a CB Cap, could be a little louder. It's been a while since I shot any, but that's what came to mind when I shot it. I shot them inside my house out an open door, and didn't need hearing protection.

On reduced charges in general, for old black powder loads, the given
to load them with smokeless powder, is to take the BP weight and use instead 29% of the BP load with 4198, which gives about the same velocity. With a 45-70, this amounts to about 21.7 of 4198, and doesn't come close to reaching 50% of the case capacity, but you don't hear them blowing up. Maybe case design has something to do with it.

Also, crimping bullets might be a thing to do to reduce the primer snap, if we're talking about the same thing. The bullets I'm using have a crimping groove so I might try that.

The silencer really shines with full-house loads. No, it doesn't make them silent, but sure makes them a LOT less noisy, and reduces recoil significantly. Get a lot of barrel heat after a few rounds.

Not nit picking but a Jar/jug is 9 ounces not 9 grains. I've got three jars coming from powder valley to do some subsonics in .223


Mike

LOL. Yes, you are right. Thanks for the catch.

I would suggest an email to Johan, who is the senior ballistician at Accurate powder co. He's been quite helpful to me recently in developing some reduced loads. I would think that AA5744 would be the answer to your problem. No filler needed with this powder!

Sorry I no longer have the link, but go to AA's site, and use the contact us link there.

That is useful info as I like to dink and plink around with my .30-30 and cast bullets. I don't see that on the Hodgdon website or the IMR website. Do you have a link to that information?

The Hodgdon site has Trail Boss loads for the 30-30 from 997 fps to 1195 fps.

Gene

Buy the Oregon Trail bullets without the gas checks. These are not terribly expensive and they perform well at the low velocities.

I have loaded a little for several suppressed rifles. The 45-70 and the 7.62 X 39 are very easy to load accurate ammunition for.
The 45-70 with 18.5� barrel in the unsuppressed Marlin Guide Gun delivers excellent accuracy beyond 50 yards using the Lyman 535-grain 457132 bullet ahead of 2.5 grains of Alliant Bullseye. This load giving between 398 and 416 fps in our powder position tests. Fed through the magazine these are good walking around cartridges and the primer is the only significant noise. The pigs are very alert to this type of �pop� and it is necessary to back off beyond 75 yards if you want more than one shot.
The laser Cast 500-grain flat nose ahead of 3.2 grains of Alliant Bullseye gives 419 fps from the suppressed NEF Handi rifle using a suppressor from Johns Guns. This is a very accurate and quite powerful combination. The sound of the primer is most noticeable behind the firearm rather than out front.

Two equally good and more powerful loads in the same rifle are 8.0 grains of Alliant Bullseye for 825 fps and 9.0 grains of Accurate Arms No.2 for 861 fps. Bullets from these two loads do not seem to run out of steam and penetrate very well.

Both Accurate No 2 and Bullseye will give you single digit extreme spreads in hunting situations where you cannot take time to position the powder in the case prior to loading and firing.

The 7.62 X 39mm has proven to be very adaptable to sub sonic loading. Using the Lee 155-grain gas check bullet (the lube groove bullet not the tumble lube version) I have been able to load some very accurate low velocity ammunition for the SKS and the AK-47.
The load of choice for the 18.5� barrel AK is 5.0 grains of Alliant Bullseye which delivers 1,092 fps and excellent accuracy. This load will not work the action which could be modified by opening the gas port.

I have varied the crimp from none to a heavy using the Lee factory crimp die. Crimp does change the velocity but with the fast powders does not seem to have a significant affect on extreme spreads or accuracy � as long as all of the cartridges are crimped the same.
The low velocity loads are an excellent way to improve your bench technique. You need to handle the rifle the same way every time or you will experience flyers using ammunition of known accuracy.

The suppressors do not seem to have problems with cast bullets. Spray cleaners work well on them.

While not the complete anwer to SEE the article by Charles e. Petty in the June/July 1997 issue of Handloader titled: "Mystery Solved" is a good start for why some rifles come apart.

Yes, I saw those, thanks.

Its the part about measuring where a bullet base is and using that volume as a benchmark for a weight measurement that I was interested in reading. That could apply to reduced loads in several rifles.

The info is from a document that Hodgdon/IMR tech support sent me about a week ago. Unfortunately, it's a PDF that is too big to zip and post here. It isn't any more complicated than what I outlined: A 100%, uncompressed Trail Boss load is safe for pressure for all cartridges. 70% of that is always safe for a starting load.

Okay, thanks, I'll go with that. Just being anal, I always like to read the source documents.

The gun I tinkered the most with mild loads was my 35 whelen ackley. I shot alot of cast pistol bullets in the 150-200 gr range from 700-1700 fps. I found that with Unique, I could get good accuracy at 1200 fps and consistant velocities, and the powder was not sensitive to position in the case. When I backed down to ~700 fps the velocities had a large swing and powder position was sensitive. A dab of toilet paper will hold the powder over the primer and keep velocities more consistant, but you probably don't want tp going through your can. I'd imagine bullseye or red dot would provide subsonic non position sensitive loads. With cast plinker loads you should be able to get 5-10 shot 1" groups at 50 yds, and the can should quiet them right down.

The advantage to the fastest powders is both the small quantity of powder and hence gas for the supressor to deal with, and the faster powders have less pressure at the time the bullet leaves the can.

So long as the bullets are being stabalized, there should be no problem using a can, it's just an upsized 22rf.

Ut oooo, I think we gotta assisian on our hands! he has a silancer, hope BATF is keyed in on him! or maybe he has a license?..maybe he is a terriost, but not a very good one because no reputalbe terriost would try and silance a 300 win mag for goodness sakes.! but hey, the guys from Georgia, those bubbas use beer cans to make silencers to jacklight deer, thats what we got here.:):):)

Just haveing some fun guys, don't get yer shorts in a wad...

I'm sure the Dems would be happy to investigate it for you, at taxpayer expense!!!

I chronographed 170 gr. .30 caliber bullets with 10 gr. of Trailboss. Getting 750 FPS. They're pretty quiet, as you'd think.

I'm going up on the load next time and shoot for 1000 fps.

MIsprint: make that 650 fps.

I think jacklighting for deer is a thing of the past. So many deer around here, it's like jacklighting for starlings.

Starlings?, I don't care who ya are, that's funny! Georgia has so many deer the game wardens tell you were to poach I am told!