interesting checks verces no checks

[Bullshop]

http://img.photobucket.com/albums/v239/bullshop/6d815e59.jpg

Here at BS acres we shoot lots and lots of cast 22's for fun and in persuit of small edible creatures. The component cost of most loads is about equal for primer, powder and gas check. Cost for the boolit is so small I wont even count it.
What I hoped for was a load that would equal the 22 wmr for as cheap as possible. By eliminating the gas check I would reduce cost by 1/3.
What I found out answers some questions I regulerly see posted here and also raises a couple new ones. I decieded to do a test with an iron sighted 22 hornet.
These type of loads will be used for ranges less than 100 yards so this rifle was fine for the test. The primer used is not the most accurate for the load but worked OK and we have an abundent supply.
One powder I have found to be well suited to the hornet and cast is Alliant Steel. The load tested was with the NEI #2 cast in ww at 625F quenched at .226" and speed green lube, 5gn Alliant Steel, and a CCI small pistal mag primer. The load shoots better with Rem 71/2 srbr but I wanted to save my dwindling supply. Average muzzle velocity was right at 1800 fps
I shot each one three times and each time the load without checks averaged better than with checks.
In this case thats the way it worked out, not to say thats always the way it will be. So will gas check designs shoot good without a check? In this case yes. Can a boolit without a check equal velocity of a checked one? In this case yes. I also often see advice given that PB boolits are restricted to BP velocities, in this case not.
This makes me wonder what is the breaking point in velocity at which the gas check will make a differance. I plan to God willing continue this test to see just how fast a w/o can go and still equal the accuracy of its checked twin. Not that I think I need more speed quite the contrary I am quite satisfied with a 48gn flat nose boolit doing 1800 fps for small game and plinking. But it has just got me curious to know just when I realy have to add that extra 1.5 cent per load.
Through out this shooting I could detect no differance in barrel condition between with and w/o loads. There was no leading at this velocity with eather. So I guess more fun is yet to come and at least with this rifle and boolit I will have some deffinite answers to questions I often see asked here.
BIC/BS

[S.R.Custom]

Interesting... Do you have a pic and/or scan of the bullet used?

I have a hypothesis that the gas check style bullets that shoot the best w/o gas checks are the ones with the thickest driving band closest to the powder charge. Thoughts?

[35remington]

I can't decide whether to be impressed or not unless I know the range. How far?

Shot as fast as possible with the barrel heated up? What do you attribute the flyer in the w/o group to? Did you weigh the bullets or segregate in any way?

If that was 100 yards the smaller group (without the flyer) would be better than what my K-Hornet would do with anything but is not so hot compared to what my other scoped .22 centerfires will do. Your iron sight shooting is pretty good, though.

[357maximum]

I hope to hear more............


I too believe in the thick driving band, be it plain based or gc

I am no physicist, but it makes sense to me that the base takes most of the punishment so a thicker foundation should make for a better boolit. JMHO

[Dale53]

Bullshop;
This is an interesting thread. As you know, I have been working with the .314"x120 group buy mould and using that bullet (plain base) in my .32 H&R Mag in my TC Contender Carbine. I have driven it over 1700 fps with no leading and respectable accuracy at fifty yards. I backed off the velocity as it is too hot for my revolver and I want combo loads. Later this spring, I'll maybe see how hot it can be driven before accuracy goes to pot (normally happens before it starts leading). Of course, I will be checking it out at 100 yards. At least that is my goal.

Gas checks can be powerful tools when you are trying to drive a soft bullet (to enhance expansion) at relatively high velocities. When you do not need expansion, however, you can get quite respectable velocities, at least sometimes with a plain base bullet.

Then, a separate issue, I believe, is what you can do with a gas check design without the check (the question you have posed).

Dale53

[Bass Ackward]

Dan,

Good testing. Gives us something to think about. Here's some more.

Remember that there are basically two forces that destroy a cast bullet. Pressure on the base that increases with inertia, and rotational force.

Pressure is accumulative on a boolits base with the weight of a bullet. This favors a 22 caliber and a light one at that. Amazing that faster powder for cartridge is working that well. have you tried the slower?

Second point is that a 22 has the best rifling height to bullet diameter ratio of any bore size. This also favors the 22 in not needing the strength of a GC.

[versifier]

Well, the next logical step is to see what happens with harder and softer alloys with the same loads. Is the accuracy difference between with and w/o consistant?
Then up to 6mm boolits. Maybe out of a Whisper class case or something similar with small powder capacity.

[Bullshop]

http://img.photobucket.com/albums/v239/bullshop/81d2f9fe.jpg

Hear is a twist from yesterdays test. As I mentioned yesterday that load shot better with a rfle primer and with a gas check but I had not tried the rifle primer without the check.
Thought I should give it a go before I moved up the velocity scale. There should be five shots with an X but one was high enough it was cut off from the pic but just out of view high is another X
The X shots are w/o check. The group at center is with and as usual with the Rem 71/2 SRBR primer shot quite a bit better than the pistal primers yesterday.
Thought I would try what I know to be a very mild primer the Fed #100 SP. Results of that were same as yesterday with both with and W/O checks averaging about the same but not nearly as good as with check and the rifle primer.
OK Bass analyze!
BIC/BS

[Bass Ackward]

OK Bass analyze!
BIC/BS


Dan,

I would say that this is a classic example of how a faster powder per cartridge doesn't necessarily guarantee better ignition. Especially with lead. Remember that shotgun primers tend to be very hot because the cartridges operate at relitively low pressures.

This is why I disagree with 44man that magnum primers "always" blow your groups. Magnum primers work better for me up until I get to a certain pressure level. That pressure "level" varies with different powders.

Got any magnum primers to try? If so, drop about .2 grain and have at it.

[44man]

Bass, first you have read me wrong! I use a lot of magnum primers. It is ONLY in the .44 and .45 with 296 powder that I have trouble with magnum primers. These two calibers have to be tested and LOADS WORKED with both primers to see what works best. I never get tight groups with the mag primers in THESE TWO calibers. Other calibers and cases REQUIRE mag primers for accuracy. So please, don't generalize what I have said.
Some cases and powders need the SRP or LRP and some need the magnum versions to get accuracy and each one has to be tested and loads worked again any time a primer is changed. You can not use the same powder charge that shoots tight groups with one primer and change the primer without doing the load workup again.
I can see that with Bullshops results. HE HAS CHANGED THE VELOCITY by changing primers! I bet he is using the same powder charge without again working the load.
Now, lets look at the boolit without a gas check. You have to come to your own conclusions though.
First, there is no difference between this boolit and a boat tail or bevel base. The most important thing is how much drive band does the boolit have in relation to the twist and velocity? If the boolit shoots great without the check and you change either the twist or velocity, you are not meeting the requirements anymore.
Let's make it easy; if you have a perfect load with the check and then remove it, accuracy will be gone, if you have a perfect load without the check and then add one, accuracy will again be gone. If you put the load in a gun with a different twist rate, you are in the same boat without a paddle and if you change primers with the resulting velocity change, you are not only in the same boat, but you lost the bailing bucket.
If you change one thing on a good load and it goes to pot, you have to change something else to bring back the accuracy. No free lunch and no miracles.
I have to wonder how many of you have tried to shoot a round ball out of one of the new 1 in 26 twist muzzle loaders made for long bullets? And here you try to do the same thing with a modern cartridge rifle, thinking it doesn't matter!

[Bass Ackward]

Bass, first you have read me wrong! I use a lot of magnum primers. It is ONLY in the .44 and .45 with 296 powder that I have trouble with magnum primers.


44,

Why by golly I did. My mistake. Sorry.

[44man]

No need to apologize, everyone else does the same thing! We have to read every post very carefully to pick up those little nuggets. I do the same thing and miss things that are important.
You do very good work and I admire you, but like the rest of us, you sometimes forget the little things. I am so guilty of this that , well, you understand.
For instance, my BFR 45-70 quit shooting tight groups. I looked at everything and went back to the #**#@ bullets and they still won't shoot. I worked on my mould too. I changed back to a scope instead of the red dot with no change.
Then it dawned on me; I use LR primers and the mainspring might have weakened. I had trouble with this spring before and it actually stop firing primers so I replaced it. I am ready to go down and shoot right now to see if adding a spacer under the spring will bring back accuracy. If it does, I will switch to LP magnum primers to see what happens.
After all the preaching I have done to you guys that the mainspring has to be strong, I FORGOT!
I will let you know what happened. *&%$^#! Ruger springs!

[44man]

OK, guys, I shot 50 rounds with 2 different powders. I used the Hornady 300 gr HP. I had 2 flyers that were my fault. I worked from minimum to max for a class III rifle and no groups were over 2" and I had some down to 1" at 50 yd's.
I was getting 3" to 6" groups before I added the spacer under the mainspring.
PROBLEM SOLVED.
Now to try LP mag primers to replace the LR primers.
I notice the gun was louder too.
As you guys say; ignition, ignition!

[w30wcf]

Bullshop,

Thank you for the interesting data. I too shoot a fair number of .22 cast bullets in my Hornet and KHornet. Bullets used are mostly the NEI 45 gr., Lyman's 225438 and 225415. I have shot some of these bullets without the gas check but only up to 1,500 f.p.s. and they grouped about as well as with the gas check on board.
My alloy is air cooled w.w +2% tin.

Based on your results, I'll have to see how fast I can push a 45 gr. .22 bullet in my alloy before accuracy starts to deteriorate. I have had success with a plain based 100 gr. cast bullet in the .30-30 at 1,750 f.p.s. The lower sectional density of this bullet and the .22 caliber bullet plays an important role on how fast a non g.c.'d bullet can be pushed an still retain accuracy.

Using the 12 b.h.n. alloy mentioned, I have pushed gas checked versions of the .22 bullets to Hornet velocities (2,650 f.p.s.) with accuracy that rivals their jacketed counterparts. Try that with higher sectional density bullets and accuracy goes out the window.

One thing I have found that allows me to produce "match grade" .22 bullets consistantly is to use new sprue plates with a .062" sprue hole. Also, the faster casting cycle keeps the molds up to temperature.

Thank you again for the report.

44Man,
That's some GREAT shooting with a handgun! I would be challanged to do that on a consistant basis with one of my leverguns.

w30wcf

[BOOM BOOM]

HI,
I will be running this type of experament with a ruger BH 357 & a RH 44 this summer when the @#$* weather gets better so the range dries out. It is a mud hole right now.
Ut. weather 2 days sun, 2 days rain, & a 1" of snow today.
So I luber 300 357s.
Keep up the good work, educational to say the least!