Backwards 45/70 gas check

[Nardoo]

Further to my senseless quest for maximum velocity in my Ruger 45/70, I tried using gas checks backwards. Stupid, I know.

I could not get more than around 1700 fps with my CBE 460-500 plain base bullets before accuracy went out the window. They drop at nearly 520 gns made from ww plus 2% Sn and shoot really well at realistic levels.

Wanting more, I tried loading them with a gas check inserted into the case backwards between the powder and the boolit. I maxed out with 53 gns of H4895 averaging 1880 fps. Accuracy is around 1 1/2" at 55 yds, below what the gun is capable of, but certainly adequate for hunting. This is a compressed load and I cannot actually fit any more powder in the case. I checked the barrel after each shot to make sure the GC did not hang up.

In the pic you can see a gas check that I picked up about 10 feet in from the target. Don't know how it got there. I figured the gas check would separate from the boolit straight away, in fact I was worried about the chrony. I now plan to make some of Bruce B's soft noses.

Now my question is, what is going on with the gas check in flight? The one I found certainly does not look like what I expected. And am I flirting with danger?



Nardoo

[44man]

The check is being blown into the boolits base, destroying it. Not good for accuracy. Why not try harder boolits an LDPE wad or a felt wad to see what happens?
That bulge in the check must have made a depression in the boolit base.

[hs45/70]

Reloading of any cartridges carries with it implied risk , even if you never stray from published load methods and data.....for those that wander into areas not commonly travelled , the possibility of further risk is naturally increased.

Not everyones' comfort zone is the same and if reversed gas checks increase your accuracy with high velocity plain base bullets and you have assembled your loads properly it may never be an issue.

I have a Ruger #3 in 45/70 and mostly shoot GC cast. however my first mold was a 330gr Lyman PB Hpt. and found it to be fairly accurate to 1400 fps. By placing a reversed gas check under the base and over 45.7 grains of Re 7 my readings were 1752..1758..1739 fps and the group at 100yards was 0.95 inch. With out GC they were over 3 inch groups.
These castings were the 330Lyman with the HP pin removed and a BB inserted in the hole to get a 350 grain by weight bullet. When I first used this proceedure I too checked the bore each shot to make sure the GC cleared..and did so for the next 50-60 rounds fired, after that I never looked again.

For my .444 Marlin, microgrooove I had a NEI 315 gr. PBase to try that I had purchased for my T/C pistol in .430 JDJ. It was quite accurate and even in my Ruger .44 SBH shot well.
At about 1400 fps it shot very well in the .444 but at 2000 fps it was marginal at best. Useing a reversed GC under the base, over a built up to max load of H335
at 2052..2067..2037 fps the rifle shot 1.75 inch at 100 yds. which I considered to be good for my hunting purposes .

I learned this process from someone who'd been there before me and respected his opinion. Could you stick a reversed GC in the bore.. possibly, but the proceedure through many hundreds of shots ( in RIFLES only !!) is within my comfort zone.

If this seems an unsafe proceedure to you , please disregard.


Max

[OLPDon]

My guess for the deformation of gas check more so happened upon leaving the muzzle causing it to mushroom I don't think there was that much deformation on the bullet base. The check sides are unsupported by the bullet base and it reacts to pressure when it leaves the barrel it gives way. Understandably it has some effect to the base of the boolit and any change in base that is not constant will hurt down range. Harder alloy might get you your desired speed, with that thump to your torso that you must realy love.
Don

[JeffinNZ]

I am driving an 8 BHN PB bullet out of my .38/303 at 1700fps on 100% load density of W748 with only a .060 card wad under it. Shoots sub MOA.

[454PB]

I used to do this in my Marlin 45/70, and fired hundreds of rounds with no problem. Then one day, I nearly ringed the chamber and changed my ways.

[Larry Gibson]

I used to do this in my Marlin 45/70, and fired hundreds of rounds with no problem. Then one day, I nearly ringed the chamber and changed my ways.

I would think for the price of GCs these days and ease of use I'd just get a Lee C457-500-F and not worry about it. They are less than $20 with handles. I've had that mould for 30 years and get groups at 100 yards with it's bullets like you're getting at 50 yards and mine are pushing 2050 fps. I've seen Rugers do the same. But I've been known to keep trying to make a silk purse out of a sow's ear too! 44man is correct about them apparently deforming the base of the bullet. Just my thoughts.

Larry Gibson

[Char-Gar]

Oh Pooh on the Nah-Sayers... What you did was a fairly common practice in the Days of Yore. I have fired many hundreds of 45-70's with inverted gas checks and big doses of powder. Yes, the cup shape of the check occured as it left the muzzle. I have retreived many bullets loaded over inverted gas checks and there was no damage to the base.

[454PB]

Larry, that's exactly what I did. After giving up on the backward gas checks, I used that Lee boolit up until I sold the rifle and mould. Years latter, my son bought a Marlin 45/70, and I bought another Lee mould to feed it.

I didn't mention it in my first post, but I also owned a .444 Marlin, and had similar experiences with it. I experimented with card wads, fillers, etc. and finally decided that none of it was safe or effective. Gas checks were fairly cheap back then, and they fit a lot better right side up.

[Sundogg1911]

I'd be more worried about the Chronograph. I've seen them destroyed from a lose GC.

[44man]

The loose upside down check must be on the powder and touching the boolit, no air gap. Same with all other wads. If the powder charge does not reach the boolit, do not use anything but a boolit with a gas check on the base.
Since Nardoo said the load is compressed, it is safe.
It is possible that the check is blown as it leaves the muzzle. I never found a need for them so I don't know for sure. Harder boolits work better.

[Nardoo]

Thanks for the help guys. I know I am going about things the wrong way. There is a reason behind all this but sometimes I get sidetracked!

I am waiting for one of Boomers 462-420 GC Group Buys. When it comes I will stop all this nonsense, I promise.

Nardoo

[The Dust Collector]

I have been using the lyman 457124 cast boolit for many years with excellent results. My Ruger #1, #3 & Browning 95 have more than acceptable preformance.
With 50 grains of Reloder 7, a Winchester LR primer and a .042" waxed card.
The alloy is straight WW of a hardness of 11.5 Brinell. Dropped right out of the mould into ice water making for a 25 Brinell. These drop from my mould with a diameter of .4597". I size these in a .460 sizing die to lube only.
Lubrication is a home made blend that has worked better for me than most lubes and has a very high melting temperature and yet remains pliable enough to be used in a RCBS lubricator with out heating it.
A .462" punch ( that I made ) cuts cards from matting stock left overs. This matting is the stuff that picture framing folks use to make boarders around pictures. This is high quality card stock and is free from most places that I have asked for it.
After punching these cards, I soak them in melted beeswax untill they stop bubbling. Then they are dumped into a screen strainer to separate the cards from the wax and are tossed about in the strainer untill cool enough that they don't stick together. These are the put into a paper bag and shook with talcum powder.
I fingure start these cards in the case mouth and finnish by seating the boolit on top of the card.
The O.A.L of the completed cartridge is 2.590". I haven"t used gas checks for years.
22" barrel : 1890 fps 28" barrel: 1950 fps. Averages
This works so well for me that I have no intentions of changing.

[Nardoo]

Collector,
Does not sound like you have been collecting much dust with those loads! Very interesting approach with those waxed card wads. I too have a Lyman 457-124 but mine drops at .457". I have tried beagling, bumping and backwards gc's and the thing still it shoots terrible. My Ruger insists on boolits .460" plus.

It was OK in my old Marlin but has not shot well in my Ruger or Rolling Block. I even had it hollow pointed so I can throw them solid or HP. I tried three different mandrel lengths giving weights from 320 gns to 380 gns and even though it throws pretty bullets my rifles do not like it for some reason. What do you think?



Nardoo

[VTDW]

Nardoo,

Good on you!! I have been doing nearly the same thing with inverted gas checks attempting to push a 200 gr plain base hard cast thru my .444. I still have a few loads left in my ladder test but expect to approach 2,800 fps. I want to see what the trajectory is out to 200 yd. I am shooting 4 shot groups and most times I get two holes touching at 50 yd and the other two shots make a 2-3" group. Once I finish the test I just may epoxy on the gas checks to see how the groups are. Like you this one is just for funsies and I will most likely get in on the upcoming group buy for a similar boolit but gas checked and then sell the plain base mould.

My go to is a 280 gr (as dropped) RD 44. caliber tumble lube. Wreaks havoc on nasty old hawgs. I shoot the same RD boolit out of my three .444's and Redhawk .44Mag. One size fits all in my arsenal.

Dave

[hs45/70]

454 PB.........I know what a ringed or unringed chamber is but I don't know what a nearly ringed chamber is.. could you elaborate in the event I recognize it comeing on..

44 Man....would agree with your premise that air between gascheck and bullet base is dangerous especially a loose GC..you say you don't use GC's and i don't know if you have never used one or just don't anymore.

An unsized reversed gas check placed into a sized 45/70 or .444 marlin case requires a certain force to push it into the case a quarter inch and then seat the bullet on top and then to seat both as one unit at the proper depth...this is not a " loose" gascheck situation and it matters not if you have 20 or 50 grains of powder under it.

Have used an inertia bullet puller and pulled a few dozen bullets when I started this proceedure many years ago and the gas checks refuse to come out no matter what you try, and from all indications are wedged to the depth originally seated.

I am not reccomending reversed gas checks to anyone....just explaining why I use them and find them to be beneficial to haveing plain base bullets get accuracy at higher speeds than 1400 fps..