Marlin Firearms Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
216 Posts
Discussion Starter · #1 ·
I just purchased some lead rifle bullets from the Missouri Bullet Company, 165 gr .30 caliber for the 30-30 and 405 gr bullets for 45-70. I have also purchase some Hornady .45 gas checks, and I need to buy some .30 gas checks. I have the Lee .457 sizing die coming.

These bullets:





This sizing / crimping die:



Having said this, when reloading, I see data for 405 gr bullets. I have not received the gas checks yet, but I am positive they have mass, and when crimped to the base of a lead bullet they must increase it.

I have never gas checked a lead bullet and I have never reloaded with gas checks. I have the correct Lee sizing die / crimper coming for the 45-70 and I intend to gas check a hundred or so to have them handy.

The lead bullets are Brinnel 18 hardness. I do not want to drive them too fast but I want to make some higher power loads, and will drive them about 1600 FPS using I 4895 or X-Term. Also the 30-30 rounds are going into a micro grooved rifle and there's a lot of chatter that they lead at higher velocities and are not that accurate, hence gas checks for the 30-30.

I have several questions.

1. How much mass does a gas check add? I will of course weight them when they arrive and the final product as well.
2. If load data is for a lead bullet at 405 grains, how do you adjust for the added mass of the gas check?
3. It is my understanding that a gas check changes the drag of the bullet in the barrel. Is there any formula or reference for reloading with gas checks? I have five reloading manuals and no data with gas checks.

In summary, what difference is there when loading lead bullets with gas checks and what should I know before starting?

Thank you in advance for sharing your experience.

D
 

·
Super Moderator
Joined
·
7,958 Posts
The bullet needs to be designed for a gas check.
 

·
Super Moderator
Joined
·
12,039 Posts
Honestly of the two calibers you're gas checking the wrong one.
45-70 is not a fighter jet - more like a howitzer. Big and slow is teh way to go.
The thuty thuty on the other hand can in fact send 'em swiftly and as such could use the gas check.
 

·
Registered
Joined
·
216 Posts
Discussion Starter · #5 ·
I obviously missed the point early on that the bullets need to be cast for the gas checks. I do not want to cast my own, but I would like to buy them as cast. Does anyone know where I could acquire 30-30 and 45-70 as cast bullets designed to have gas checks?

D
 

·
Premium Member
Joined
·
565 Posts
Most bullets sold commercally that are intended for gas check use normally come sized and with the gas checks installed. If you're intent on installing your own and sizing, you might check with a cast bullet vendor to see if they'd sell you some without them. Heck, if you're doing that you might as well take the next step(s) and cast your own, IMO.

Lastly, what is your intended velocity you want to shoot these? Plain based lead SHOULD shoot fine up to 1100-1200fps (or faster if the bullet is sized correctly for your bore).

- Tim
 

·
Registered
Joined
·
4,106 Posts
I don't own or load for a 45-70 but those I know who do shoot cast at .459-.460 diameter. So I suspect even if those were designed for gas check you would of had problems with leading and accuracy. Those that load for that caliber can correct me if I'm wrong but at as stated by others, 1600 fps and below doesn't really need gas checks if they are sized correctly for your gun.

As for the accuracy of a microgroove barrel, as long as you shoot casts that are .002-.003 larger than barrel groove diameter the microgroove barrel is just as accurate and lead free as any other barrel. I shoot .310-.311 in my Marlin microgroove barrel and they shoot just fine.

Load data for gas checked or bare bottom cast is the same for both. No need worry about different data. The gas checks themselves will add a few grains of weight but just use the data that is available for that particular cast. The gas checks themselves will not put any noticeable drag on the bullet if any to matter.
 

·
Banned
Joined
·
651 Posts
I do not use gas checks in my 45-70 loads. What I do use is Johns Vegetable wads. They are .060 inches thick and place over the powder before seating bullet. This helps with leading if you are going to use hotter loads. The copper gas checks are so light I would think it would not add a significant mass to the bullet.
 

·
El Kabong
Joined
·
8,333 Posts
You dont need gas checks for 45/70s that go 1600fps, I have gone 1750fps with much softer (15bhn) boolits and never leaded yet.

The 30-30 on the other hnad should if you gonna breech 1700fps. Mrs Pard's 1949 Winnie shoots 170gr ranchdogs right at 1600fps, dont really need to be checked at all.

Ive pushed that same boolit to 2500fps (out of an odd six) with special lube and harder boolits with no leading.

Stop buying stuff, and start making it.

Pat Matin's check makers are the bomb, and I have one for each caliber I have a gas check mold for.
 

·
Registered
Joined
·
4,559 Posts
To gas check or not to gas check, that could be the question.

As said early on, the bullet must be designed for a Gas Check before one can be seated.

Then the comment was made that below a certain velocity level gas check are not needed to prevent leading.

Now, if the bullet to bore fit is proper and your bore is good that may be true.

However, a point that has not been addressed is. Some rifles prefer gas checked bullets to non-gas checked bullets, and other then the additional cost, they seldom hurt accuracy.

An internet friend in Ohio has been almost to the hair pulling stage trying to get his 45/70 rifle to shoot plain base bullets. He has been testing varying bullets, powders and loads and was about to the point of throwing in the towel.

Then he tried, over his own very vocal objections some gas bullets only to find that the groups greatly improved, fliers decreased and the groups rounded out.

So, the point is while the gas checks may not be needed, they may well be of some benefit.

Testing is the only way to find the preference of your rifle.

Crusty Deary Ol'Coot
 

·
Premium Member
Joined
·
565 Posts
To gas check or not to gas check, that could be the question.

As said early on, the bullet must be designed for a Gas Check before one can be seated.

Then the comment was made that below a certain velocity level gas check are not needed to prevent leading.

Now, if the bullet to bore fit is proper and your bore is good that may be true.

However, a point that has not been addressed is. Some rifles prefer gas checked bullets to non-gas checked bullets, and other then the additional cost, they seldom hurt accuracy.

An internet friend in Ohio has been almost to the hair pulling stage trying to get his 45/70 rifle to shoot plain base bullets. He has been testing varying bullets, powders and loads and was about to the point of throwing in the towel.

Then he tried, over his own very vocal objections some gas bullets only to find that the groups greatly improved, fliers decreased and the groups rounded out.

So, the point is while the gas checks may not be needed, they may well be of some benefit.

Testing is the only way to find the preference of your rifle.

Crusty Deary Ol'Coot
Agreed... Also, Whilst I may (or may not) be able to get plain based lead to shoot decent in a particular gun, I've seldom found a gas checked (boolit) or jacketed (bullet) combo that didn't work well, and with much less testing/load development (regardless of the velocity desired). Don't get me wrong, I'd much prefer to shoot lead only, but the amount of time and effort I'm willing to spend on a particular gun & projectile is often limited, especally if I find a jacketed or gas-check combo that works well in it.

Also... One thing to consider... If your intent is to interchange lead and jacketed in the same gun, I've had much better luck using gas-checked boolits. I frequently have a need to shoot jacketed bullets at one target/distance and lead at another on the same day or silhouette match. If I shoot plain based lead boolits and jacketed I have to clean the barrel pretty well between to two types for the best accuracy. Whereas if I shoot gas checked and jacketed, the cleaning between the two types isn't required.

Just another .02,

- Tim
 
1 - 15 of 15 Posts
Top