Chamber pressure

[Shadow]

When reloading how do you ensure that you are not creating to much pressure. Some of the reloading manuals do not list pressures. I thy to load at about 200 to 2700 FPS. I also use mt chronogragh to chect FPS.

[High Plaines Doug r]

Garand loads are pretty standardized regarding bullet weight and powders. You would be well advised to stick to published Garand suitable loads or invest in an adjustable gas plug. To protect your gas system, if you are going to develop exotic loads, you need to be concerned about "port pressure" and you are unlikely to find much published data citing that information.

"I thy to load at about 200 to 2700 FPS"...

I don't know what you are trying to say with this phrase but using a chronograph to determine an appropriate load is asking for a bent Op Rod.

[mhb]

is that you must simply stick to published load data in the knowledge that it is developed within the industry standards for maximum pressures for the cartridges listed. Never try to exceed published data, and, stick with the conservative data unless you have a very good reason for using top loads.
You must also observe good loading practices and be watchful for indications of excess pressures or other problems with your ammunition.
I fact, unless you have equipment able to measure the actual performance of your loads, you are taking the whole thing on faith and reliance on the trustworthiness of the data source.
If you follow this advice, you are unlikely to run into trouble, but you should realize that the ammunition you load is unlikely to precisely duplicate performance of ammunition produced and tested under laboratory conditions.

mhb - Mike

[Hefights]

The chrony is a good way to help monitor for pressure. Other signs are flat primers (although cup hardness or softness can fool you), extractor marks on case head, difficulty in bolt opening / extraction, greater recoil.

Per the instructions in all loading manuals. you should work up loads from a reasonable starting point, as stated stay within published data for your bullet. Typical Garand powders are IMR 4895, H4895, and similar. For Garand you are in the range of 2,700 to 2,800 fps + -, depending upon bullet wt, purpose, powder etc.

Generally, slow burning powders (like IMR 4350 and H414) require more powder for equivalent velocity, meaning more gas, more gas pressure at the gas port, and risk of damage to rifle. As stated, way to mitigate this is adjustable gas plug like Schuster device.

[Shadow]

I'm using the chronograph in attempts to ensure that I'm within the recomended loads that the manuals call out. Not trying to create anything special. I'm using 4064 powder and 150 hornady a max bullet at 44 grains. 168 grain a max and 47 grains 4064. I'm very cautious and weight each load on a digital scale. Most loads are always arount 2500 to 2600 FPS. I use RCBS FL dies on a Dillon press. I see where some people talk about small base dies, what is a small base die?

[mhb]

is one which is designed to reduce the diameter of the base of the case to the original, unfired condition, or near to it. The theory behind this is that self-loading rifles require fired brass to be reduced to that condition for proper function.
The standard full-length resizing die does not usually work the head of the case so much as that - nor is it necessary.
In nearly 50 years of loading and reloading for self-loading rifles of many types, I've never found it necessary to use a small-base sizing die - and I don't believe you will, either.

mhb - Mike


I see where some people talk about small base dies, what is a small base die?

[Sunray]

The "chrony" tells you nothing about pressure. Chronographs tell you about velocity only.
Small base dies resize the case about 5 thou more than a regular FL die does. You must FL resize every time, but like mhb says, you really don't need an SB die for .30-06. Some AR's prefer it though. In any case, it's one or the other. Not ever both.
"...around 2500 to 2600 FPS..." Is kind of slow. .30 M2 ran at 2800 fps with a 152 grain bullet. Ditto for .30 AP's 168.
44 grains of IM4064 is 3 grains below minimum for a 150. 47 grains of IMR4064 is the starting load for both a 150 and a 168. Max is 51.0 and 50.8 respectively. You need to work up the load, not just pick one and hope it'll be accurate.

[Hefights]

In working up loads you rely on a number of tools - the manuals, reading the primers, the case & case head, the velocity, function of the rifle, and common sense. Most often shooters get to an acceptable and accurate load before getting to the limit. That is the working up part. This applies especially to the Garand for most applications.

Assume you are using data from manuals, such as Hodgdon, or Hornady's service rifle data, Sierra Manual, Lyman 49th Edition?

[Shadow]

I'm using all the noted manuals, as well as the accurate manual.

[joem]

I have found my most accurate loads use between 92% to 98% of the max load powder data. The one exception I found was a Garand load (4895) that chrono's @ 2000 FPS but it wouldn't cycle the action.

[psteinmayer]

There have been shooters who've won medals with their Garands shooting plain ole BALL ammo. I stick to the established data in the Hornady and Lyman manuals, and don't get too wrapped up in what dies, press, etc. that I'm using (I load using a 30+ year old Lee Challenger press and standard Lee dies)... and never had a problem.

[cwartyman]

The only time you should really ever need a small base sizing die to use in a garand is if you are using once fired brass that had been fired in a MG like the 1919. Otherwise a standard full length sizing die will be more than fine. The MG fired brass can be in 06 or 308 and typically has a portion of the case that needs to be resized that the FL sizing die does not touch. This has been my experience in buying brass. So if you happen to run into cases you bought and after FL sizing they give you problems chambering this could be a reason.
Mack