Breaking 120 FPE with cast 25 acp bullets
Well I tried a different fire control system in the Condor.
I had been going stock hammer and weight and spring with the RL valve stem and Condor top hat set to .1.
I suspected my spring was a little tired, I have had it for 2 years and countless thousands of shots, not to mention leaving it cocked overnight on several occasions..
Marvin was using a stiffer spring, and I had some around made of the same wire, Airarcher springs, so I went to work on the old gal this morning.
First I opened up the inside of the Airarcher spring to allow the PW to fit inside, the wire being .80 as opposed to .62 would not allow it to snap in.
Then I shortened the spring to 3.5 inches, then reset the end flat.
Next I drained all the air out of my tank and tested to make sure I was not bottoming out on the RLAirguns valve stem with it set further out. I found that at .13 top hat setting, I still had a fully spring supported valve stem.
I put it all together and started shooting over the box. Before I was averaging around 930 FPS for 100 FPE with 2800 PSI which was the mazimum PSI that I could open the valve. I gradually increased my fill to 3200 PSI, if my gauge is correct and I suspect it to read a little low, and at that PSI I hit 1013 5 yards from the muzzle.
Two things changed at that level.
My trigger which was below 1 lb, started self discharging, I am glad I have good gun handling habits and had it pointed in a safe direction. So I set it around 3 lbs for now and will play with it later.
Accuracy improved. Marvin had said when he picked up the velocity, his improved, it seems mine does also. Shooting off the top of the 58 Mercerdes in the garage without a bag, just resting on my hands on the metal of the car roof, I shot a 10 shot group that was 1 inch vetically and 3/4 inch horizontally.
Adjusting that velocity back to the muzzle gave me 1024 FPS with the 52 grain bullet and that folks according to Hand loads .com is 121 FPE.
In the field where it counts, that means with a 70 yard zero, the bullet never rises above 1.1 inches to 70 yards, and gets to 85 yards before it approaches 2 inches of drop.
Comparing it to the 25 acp, you get to the actual muzzle velocity of the pistol round at 245 yards.
I suspect once I get the sizer dies, so that less pressure is wasted sizing down that slug in the lead and bore when the air hit it, I will see both an accuracy improvement and a veloctiy improvement.
Regards,
Roachcreek
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RC,
For those stripped holes in your frame, I had this show up on my Condor early on as my rifle had so much trouble right from the get go!!!
Just go buy you some heli-coils and one kit for that size you need to use and you will never look back man…
I have done this sort of thread repair for years and just about ever thread size out there from one time to another… They do wonders in the softer alloys such as the aluminum frames on the AF rifles…
The little thread inserts are a stainless steel and once installed correctly the frame holds up perfect. The inserts look like a small spring when you are looking at them.
The kit will have you the heli-coil drill bit, tap and insert install tool. The only thing else you need will be red loctite… This one mod you can do to every tapped hole.
Now on the bushings for the barrel, with how the set screw just centers in them, I make a small sleeve from something of the right ID size, ie. steel brake line tubing or whatever, then drill the bushing out and press the sleeve in with red loctite applied with a tip of a tooth pick, so as not getting too much of the locking agent on each.
The sleeve in the bushing index holes help save the bushing as the Heli-coil will your rifle frame… Its a lot of extra time you put in on the build of the rifle and all, but well worth the effort with the end result…
Least, this will give you another choice, and ideally you do this to a new frame; before you get the holes all stipped and/or loosened up and you can expect no problems from that…
His molds are $ 125.00 . Take your time and hand lap the mold .JMO Marvin
Marvin,
I had just read that article yesterday, thanks.
It is informative, and I worry that I might end up screwing up my mold.
I still have not given up on the Ranch dog SWC mold. It would be a better diameter for my rifle, as of course would a LBT SWC mold custom ordered in any diameter I would want. The Ranchdog mold is supposed to be available on 11-07-11 and is only $60.00. Marvin do you remember how much your LBT mold cost you?
For now I think I will just try to coat the lower portion of the mold with mold prep to gain a .001 or so.
I keep wanting to pursue this, and I am considering making up a rifle just for this project. I would like a TT dogleg etac, a WOK extended trigger guard that would incorporate a forearm hanger, and the valving I have, coupled with the correct mold.
Once I get a bullet that performs how I want it to, I will send my barrel and sample bullets off to someone who can recut the lead so that my bullets are a nice tight fit to the lead.
The lead right now is a nice tight fit for what I am using, but may not work for the next mold.
BTW thanks for all the help so far on this project.
Regards,
Roachcreek
Charlie if you are still thinking of enlarging the mold here is a link that might bring back your memory . As far as the lapping goes . I have found that if I leave the cutter open and place nuts such as 5/16 or 3/8 on top of the mold and then pour I have a nut attached to the bullet that can be spun buy a socket . This eliminates the off center problem that drilling can cause .Marvin
http://www.lasc.us/Brennan_4-0_ModifyCastBullets.htm
No machines here!
Yes I know do have a lead, no punn intended.
Jerry I usually find that different molds have different charateristics for filling them, the rate to fill them, the temperture of the mold at the fill and the temperture of the lead to fill them.
Add to that the different mold materials and the different ways to keep them clean and to clean them once the get deposts on them.
It is indeed a big endeavor, but when it all comes together it is rewarding.
That little gap I spoke of on the base of the 25 caliber mold, it was the smallest caliber mold that I have owned. I at first thought it was caused by the sprue plate deforming the base when I opened the mold, and the drag on the soft material was too much for it. But it was the angle I filled it from.
I am intrigued by castiing machines, altho I have never watched one work let alone used one. Have you used them?
Regards,
Roachcreek
So “technique” counts! Yeah, I know you never said it doesn’t RC but some folks seem to think that any hairless ape can make good bullets on the first try!
SWC? I think I might have a lead on where a guy could find some of those… 😆 😆 😆
Moneyshot,
I am more inclined to try a swc rather than a HP. I do prefer the penetration on deer and coyotes on shoulder shots.
I took it out today with the heavy spring in it that I get 120 FPE, and shot at 50 yards. It shoots little tiny groups and then the flyer.
So today I cast from just one cavity to see if I could get rid of the flyer, due to the fact I use two different filling techinqiues when filling both cavities.
What I found is that if I hold the mold sideway against the ladle, I get a small gap in the base of the cavity, it may be where my flyers are coming from.
My big molds need to be filled that way, and do not suffer fronm that gap. I cast up 145 bullets with the mold level and they are much better looking bullets.
Without flyers I am in the .70 region at 50 yards.
The “white lightening” sounds interesting.
Thanks,
Roachcreek
what is your intended prey? that penetration could prove invaluable on tough hided and thick boned game, razorbacks for example. penetration is preferable to shock in some situations. id perfect the round ones, then start messin with a companion slug in hp format. one thing at a time, roach… 😉 btw, one more lube ive noticed shows promise is white lightning chain lube, it dries into basically a teflon/bn colloid fortified coating of paraffin, ive been finding a lot of use for it since i first tried it…
Moneyshot,
I really need to breakdown and get a new frame this month.
Question is on the mold, should I just have LBT make me a .254 50 grain SWC mold? Insterad of screwing more with this design?
It would cost about the same as the RCBS mold. And no matter what I do with this bullet and how good it ends up shooting, it will deliver very little shock to the target due to the roundnose.
I have also considered grinding down the little bullet shaped dremel polishing tip, to match the shape of the RCBS bullet and just polish the cavities out until it casts to the desired diameter.
Descisions.
Regards,
Roachcreek
RC,
you always do, and you always end up slightly better off every time(save for holes in your frame… 👿 ) youve spent this much time perfecting it…ride this crazy torpedo to the target! 😈 😈
I got the sizer die and the #2 Lyman alloy and cast up some bullets.
They are noticably harder and much easier to fill the bases with the #2 alloy due to the fact that it flows better.
One thing I was not happy about tho, was the fact the bullets are coming out at .252 to .2535. The sizer die is a .253 and barely touches them. My barrel is .2535 so I was a little worried about the accuracy.
I have tried various lubes with not a lot of sucess so far, so I decided to wash off the WD40 I had lubed them with for sizing and shot them dry at first.
The groups were much smaller at 35 yards, around .06 and the flyers were not there. I went into the house and got some more bullet, I had just grabbed some and cleaned them and put them in my pocket before, and these had some residual wd40 on them.
I refilled to 2800 and shot, the goups opened up again. So I inspected the bore and found that I was only getting contact with the rifling and not the lands. Sort of had a grey striped looking bore.
This morning I went out and shot some more with the new sized bullets. They were all dry and clean and I was shooting at 50 yards. I cleaned the bore and shot 7 shots from a clean bore and a 2500 PSI fill to season the bore and then shot a 50 yard group. It was .80″ for 5 shots.
I was stoked, but when I refilled to 2800 the groups went to hell again.
I at first suspected a dirty leaded bore, then when that was found to not be the case, I suspected I still had some residue of wd40, but realized I had cleaned the bullets well.
Then I suspected paralax at different scope powers, but that did not pan out either.
And it always seemed to be at the end of the fill when I would shoot tight groups.
Okay I’m slow.
It took be another 30 shots and refilling to realize that if I kept the fill level at 2300 to 2400 PSI, I would get groups under the magic inch and did not need to clean the barrel.
I then chronied the rifle at that PSI and found I am still at 930 FPS.
I would like the bullet to be a bit bigger, at least to fill the barrel completly after sizing, but this works.
I am contemplating asking Eric at HP molds if he can open it up a couple thousands. But I just don’t know if it is worth the risk.
Should I fuck with sucess?
Regards,
Roachcreek
This is a 20 shot group at 36 yards at 95 FPE and the PW at 10/11.
Shot string is recorded in reverse, ie., #20 was shot #1.
Fill was only from 2550 to 2000. Nice mild load, still some flyers, I suspect due to unsized bullets.
First 5 were into .58″.
Regards,
Roachcreek
When you get the die and size the bullets try the 120 fpe again and see if that works .Marvin
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Rowdy,
We had discussed the options earlier and most said that the helicoil would not work that well. But it sounds to me that it is a better fix.
Drilling and tapping to a bigger hole is not a good option because your dealing with the same issues, believe me I know, I have now stripped out the bigger holes and had to redrill different holes.
I will go buy a helicoil kit and start experimenting. Perhaps if I put 1/4 20 helicoil in my repaired holes, then drilled and tapped the the 1/4-20 set screw to 10/32, I can salvage my frame.
Thanks for the info.
Regards,
Roachcreek