M1 Light Loads

[Zut]

Hodgdon publishes that H4895 can safely be used down to 60% of the published max load for that powder and bullet in their reloading manuals. For instance, I shoot a 125g Speer TNT with 40g H4895 in my M1903A3 with some success. Max published load for this combination is around 53 grains, so I am at 75% of max load. On a good day for me it will shoot in the 470's, so the problem is not the rifle or load!

[Kilo-Sierra]

Originally Posted by Gewehr43

I would use the term "light bullet" loads for your applications, that to me, is the most specific and correct term. (Maybe??) And describe the secondary explosion issue as being with "light charged" loads.
It's a function of a light powder charge not burning correctly and needless to say the loads you are running have a full powder charge.
I think that is the critical distinction to be made...…….
So how about "light bullet loads" and "light powder charge" loads??????

PS......Hogdgon publishes and specifically puts in print that H4895 can be used in "light powder charge" loads...….but you'd have to pull it up and see.

I think your description is more accurate than mine.

I shot a Run 'n Gun match at TMP at one of the D-day matches. I shot a garand that was not one of my competition rifles so didn't mind blowing through a bunch of ammo and really heating it up. Anyway..I was shooting 110gr Hornady's using 42grs of H4895. It was EXTREMELY soft shooting and ran 100%. 41grs was iffy on operation so i stayed at 42grs. What's my point...? Not really sure...

Keith

[navyrifleman]

The subject of "light loads" is an interesting one to just about anyone who reloads. There are quite a few variables in reloading and also some safety rules that need to be heeded.

I consider a light load usually to be with cast bullets. If you look at any reloading manual, you see that they are loaded to produce much lower pressures than metal jacketed bullets. It is desirable to get reduced recoil, save money on powder and bullets - but one also wants to get decent accuracy, and in the case of a semi auto like the M1 be able to cycle the action.

Cowboy action shooters use reduced loads for most of their competition and practice.

Back in the day, my Dad had an 03A3 that he rebarreled and sporterized as a .458
Winchester Magnum. Using full loads for target practice was just not an option! As a 135 pound kid, I fired it with a full load and took three steps backward. My shoulder hurt for a week. Dad came up with a reduced/light load using IMR 30-31, and another IMR powder, but he also had to fill up the case with Wheatena (a fine powder cereal) to keep the powder near the primer.

Some newer powders are now available which do not require filler, but others are sensitive to their position inside the case.

The recommended starting loads in the manuals are selected for a reason. Pressure is an important part of the equation in developing a proper load. With a recommended start load, you have acceptable, safe pressure. Obviously, there is a Maximum (do not exceed) load listed for each bullet and powder type. If you compute the difference between the two and then weigh out that amount of powder, you can see how critical it is to carefully weigh and measure each charge.

Keep in mind that reloading for a semi-automatic rifle might involve a higher pressure starting load and a lower maximum load. The round has to cycle the action and not be too hot for the action. Some reloading manuals have sections dedicated to specific semi auto rifles. Bolt action rifles have a wider range of acceptable loads.

A factor to be realized in loading a much reduced powder charge is that if you accidently "double charge" the case, you might still be able to seat a bullet on top of that double charge and that mistake can lead to disaster.

Low pressure loads in a high power rifle can cause the case to not expand properly, and allow blow back gasses to hit you in the face. It can cause your casings to be sooty and might cause the primers to back out of the case. Things to watch out for.

The best practice is to begin with the manuals' Recommended Starting loads and slowly work your way up in increments as you seek the best load for your specific rifle. If your chosen powder/bullet combination does not give you the results you seek, try a different powder, again at the recommended starting load.

If you want to try more reduced loads work your way down in small increments from the recommended starting loads.

[Bml]

Originally Posted by navyrifleman

If you want to try more reduced loads work your way down in small increments from the recommended starting loads.

I would highly suggest not doing this. It is a dangerous practice. I had to drive bullets out of a 45-70 barrel because of using below minimum charges trying to make a light load. I learned from that experience using large cases with inadequate powder fill will cause incomplete burning of the powder. I could have saved a lot of trouble if I had heeded the powder manufacture and internet warnings.

If you seek light loads, find a powder that is suitable and stay within published data.

On the side conversation of high pressure issues with light loads, it is usually called detonation. There is a ton of info on the theory of the problem and if it even exists. It is a real issue on internal combustion engines and can cause severe damage to them. My theory on detonation is it more often than not an excuse people come up with rather than blame themselves for accidentally double charging a case. I have seen several times reloaded ammo has blown a pistol up or stuck a bullet in a barrel and the person first blames everything except that they possibly made a mistake reloading.

[Pinecone]

Detonation in an internal combustion engine is an ENTIRELY different thing from detonation in a firearm. Other than it being destructive.