Using RX7, questions.

[geargnasher]

I'd like to call on the aid of those of you who know a lot more about powder characteristics than I do.

I have an NEF .45 Colt of recent manufacture, and it has a very generous throat. I've found it really likes the Lee 457-340-RF sized .453" and doesn't shoot any of the eight other 230-300 grain range boolits I have tried worth a darn.

So I'd like to work up a hunting load with the Lee 340, taking the approach of splitting the difference between a .45/70 and traditional .45 Colt SAA loads. My approach with the heavy boolit is to use a medium-to-fast rifle powder like Reloader 7 or XMP5744 to get in the 1400-1500 fps range while still keeping pressures in the 20K CUP range or so. I say LIKE to, I don't know if it's reasonably possible.

The issues I can forsee are getting the powder to light with a pistol primer (even magnum primers might not do it, I don't know), possiblity of creating an SEE with not enough coals. I thought of trying cut-down .454 Casull brass, but I'm not sure the small rifle primer would be any advantage over a magnum pistol primer, although the thicker case head sure would be. I know that some brands of magnum pistol primers actually have more brisance (sp) as opposed to merely having a thicker cup and same pop as a standard primer than others, but I don't have any current data on what brands are hottest. Thoughts?

I've used RX7 quite a bit in .45/70, .45/90 Winchester, and .30-30, from mild to hot, even as much as 40% below recommended starting loads (down to what I estimate to be 14,000 CUP) and have had good success as long as I used a bit of Dacron filler, but these all had standard large rifle primers to light them.

The point here is powders like BD, 2400, LilGun, 410, 296/H110, 4227, build too much pressure too fast to launch this boolit at the speeds I'd like, but slower powders are difficult to light. Anyone have any input on this classic paradox of the cast boolit shooter before I get my Kevlar Blowproof bellhousing blanket to wrap around my gun and try this out?

TIA

Gear

[stubshaft]

Re7 has given me erratic results in the 454 and 500. It seems to have a unique pressure curve, where if optimum pressure is not reached then the powder does not fully combust. It kinda suprised me because it does work so well for me in the 45/70 also. I would try SR4759, it is slower than 4227 but ignites easily and has a broad curve. 1680/680 also comes to mind but again it has to reach adequate pressure in order to completely ignite and it can in some cases leave a hard black powder fouling.

[onondaga]

Out of the rifle powders you mention from 5744 to Rel 7, There is others between them on the burn chart. From 5744 being the fastest, they descend in order; A1680, A 2200 rated same as H4198, then A2015 rated same as Rel 7.

That 340 grain bullet I cast in #2 alloy and it weighs 329 grains for me. This is a heavy bullet for the 45 Colt and no loads are listed for that heavy a bullet in the 45 Colt.

Out of those powders, Rel 7 burns cleaner and more complete in reduced loads than 5744 in my experience. But you haven't mentioned, 4198, that is a clean burner too with pressure curves a little smoother than Rel 7, I believe. 4198 also has a good reputation with the 340 gr bullet in the 45-70.

The velocity you are hoping for doesn't look to be pressure problematic for the NEF SB2 action. The SB2 is designed to handle pressures over 50,000 PSI with the 500 S&W Mag. , Keep that in mind, you will run out of Plain Base cast bullet strength way before 50,000 PSI.

So I'd say, if you are going to work up loads with 5744 and Rel 7, A sensible thing to do would be to work up a third powder in the middle of those two that has a good reputation with that bullet weight. H4198 or IMR 4198 or A2200. Maybe you have one of those on hand.

Possibly a run of Quickload software on your selections would give you a good, safe start load and a better idea of the pressures you will be dealing with. I don't have the software , perhaps someone can help you.

Also consider figuring out which one of those powders will give you the most complete case fill at the velocity you seek, that helps ignition as you know.


Gary

[onondaga]

The Lee#2 manual page 685 lists a 45-70 load with the 340 gr lead bullet and 5744:

27.0 gr @ 1314 fps >> 30.0 Gr @ 1494 fps with 14,600 PSI in the 45-70 rifle, your pressure will be higher with the smaller capacity 45 Colt case, but I bet not more than an additional 10,000 PSI and that would be compatible with the SB2 and #2 alloy. The additional pressure will increase the velocity. If I had to hazard a start load, hmmmmm , 20 grains with BPI original filler to a 105% compressed load and a crimp. I'd Chronograph the first shot it may be right at 1500 fps. plus or minus 300 by my mental math!!!!

SAFETY NOTE: Don't rely on my mental math, Gear. Quickload will use your case capacity, bullet weight, LOA and barrel length to project velocity and pressure. I strongly suggest getting help on this one for safety. Then let me know how close I was.

Gary

[wiljen]

A quick run of QL using the lee 340 in the 45 Colt sized to .453 and loaded to an OAL of 1.580 doesn't let you get anywhere near 1500 fps using RL-7 without pressuring it way way way beyond 20,000 PSI. (my test run used an 18" barrel).

With the parameters above (assuming 20,000 PSI Max) 19gr was absolute max and only reached 1124 fps.


QL predicts the best powder choices will be Norma R123 and H110 and neither of those break 1250 with the same parameters.

[felix]

Interesting challenge, Gear. No need to worry about pressure with RL7/680. It will be less than 30K cup, filling the case to base of seated boolit. Some lots of 454 cases are too hard/thick for the load, and will result in micro cracks when shot in large chambers. The cases are actually smaller in diameter than regular 45LC cases. These two powders are the only ones I have used that will allow enough powder because of their fine granule size. Use regular primers. The powders are NOT that hard to ignite because of the boolit weight. No, not perfect ignition because of the large chamber and resulting gas escape, no matter how tight the sized case is onto the boolit. For hunting I would use sorta' new LC cases. 100 yard offhand in a 94 would allow milk jug hits on every shot using either powder. I used a 315 grainer LBT, 25 grains RL7, 28 grains 680. Notice the latter has slightly smaller granules.

If you really want to get into it, I would suggest opening the chamber of a "cheap" barrel to allow painting with a good epoxy as was suggested earlier in another thread. After cure, do a re-chamber job with a more appropriate reamer which would limit your loaded round to 0.002 max expansion. Fun and games.

... felix

[onondaga]

The barrel on The NEF Handi-Rifle is 22 inches unless modified. I don't Know the reason Gear mentioned 20K CUP as his desired pressure zone but he did say CUP and not PSI. The 20,000 CUP equals~12.4K PSI +- 3000 by conversion and is an unrealistically low value to approach 1500 fps with a 340 gr bullet in a 45 Colt rifle.

I don't know if Gear wishes the low pressure for the rifle safety or for the recoil factor or for the alloy selection. In any case the rifle will handle 50K psi and #2 alloy will handle 20K psi with a PB bullet and just obturate.

With a PB bullet, I'd go by the Lee hardness/pressure chart for selecting an alloy based on the pressure Quickload spits out.and get the alloy 10% more in ultimate compressive strength in PSI than the load pressure spit out in PSI.

I do see this as challenging and powder selection will be a very important factor due to the available volume of the 45Colt with the long bullet Gear has chosen. COL with the bullet .010 off the lands could used to determine the maximum volume available for a powder charge and the Lee VMD chart will tell the volume of a selected charge to see if/how it fits in the available room.

I don't know how much room Gear has but the VMD factor for ACC 5744 is .07515 so 20 grains will equal 1.503 cc volume.
Rel 7 VMD = .07280
H4198 VMD = .07500

Once COL and the max available powder room is calculated a Quickload wizard guy would be great. http://castboolits.gunloads.com/member.php?u=6250 , NHLever, Chuck really helped me.

I do think Gear will need a faster powder like LilGun, H110, A4100, SR4759 or WC820 to get to 1400-1500 fps with the 340 gr bullet. I'd recommend Starline Brass first also.


Gary

``

[wiljen]

I caught the CUP thing but assumed he meant PSI as cup would have been too low to be useful for anything. Thanks for the heads up on the barrel length, I'll alter it in QL and try the #s again.

[wiljen]

Ok, reworked a few things. Loaded long assuming your barrel allows an OAL of 1.88 (leaves only .263 in the case) you can get nearly 1500 fps with Rl-7 and keep pressure to below 22,000 PSI (not CUP)

27gr of Rl-7 gives 1437 from a 22 inch barrel according to QL at 21,035 PSI. if you shorten the OAL, pressure climbs pretty quick.

[geargnasher]

Thank you so much, Gentlemen, I was expecting an onrush of uneducated guesses and panicky warnings about going away from published loads, but this is GOOD STUFF.

First, let me clarify some things. I DID mean CUP, not PSI, and I picked that as an arbitrary target number more or less since it falls in the +P .45 Colt category, I'm not as familiar with pressure/weight/velocity figures with straight-wall big bores as I am with bottlenecked .30 calibers and smaller. I'm well aware of the capability of the platform, they make it in .30-'06 and .500 S&W Magnum, and lots of guys bore the .45 Colt chamber deeper for the Casull and shoot full-house loads, but they also fill the stock with lead and have bigger tires on their trucks than I do. This gun weighs around six pounds and has a steel buttplate! I'm more concerned about the strength of the brass case with regard to pressure, I figure pressure needs to be less than .44 Magnum operating pressures to be safe. I picked 1400-1500 fps because I wanted to stay supersonic to 100 yards, with a little room to spare.

I try not to be the lazy fool who always askes if someone (who ponied-up the bucks) would "run a load on Quickload for me", since I haven't provided any of the info needed for that like bearing surface (including land depth, width, and number), boolit BHN, exact COAL, distance form lands, chamber neck clearance, ad nauseum. But THANK YOU WILL for doing that anyway, it paints a clearer picture. This gun is a Classic Carbine with a 20" barrel, FWIW.

I have a can of IMR 4198, but I was thinking RX7 due to loading density. I can get 28.5 grains in a resized case to get 100% density (no compression) at my optimum COAL. I was figuring on starting with about half that much and some Dacron, work up from there and see if I could get full load density and still maintain safety, accuracy, and shootability. I like the BPI idea even better than Dacron for ignition purposes, compressing the powder some would help. I've fired a ton of lead with 505 and 535 grain boolits in .45/90 with 36-38 grains of RX7 being optimal for the gun, but even in a 13-lb Shiloh Sharps it is all I want to shoot 20 rounds.

I think I have enough to go on here, once I get a safe place to start I can do most of it on my own with a chronograph and common sense. I'm thinking about starting with CCI standard primers, about 18 grains of RX7 and squish it down slightly with some BPI to a little over 100% density. Good enough to try?

Thanks again!

Gear

[onondaga]

Sounds like a good place to start. If you have a Lyman #55 measure with the clapper, they throw BPI very well with a with a clap at the end of each stroke direction.

Gary

[geargnasher]

Good tip, but I found the appropriate Lee dipper, scoop carefully without packing, card off the top, and dump in the funnel. I was thinking ahead and wondering if I could fit two Lee measures on my Lee Turret press, but I figured that the BPI wouldn't feed very well even with a Pro Autodisk. I'll try it out at some point since I have an extra riser and swivel base.

Gear

[geargnasher]

I got a chance to go to my range right after work, fired two test groups of five and I'm very encouraged. The CCI 300 large pistol primers did the trick just like you said, Felix.

First round was 18 grains RX7 with six grains of BPI Original on top, about 1/16" compression when the boolit was seated. Mild recoil, got a 1-1/4", round group at 25 yards, a pinch of yellow powder grain hulls in the barrel which I puffed right out with the black smoke after each shot. Dry-patched after five, bore looked excellent, no leading and no stuck-on residue, and no pressure signs. I "neck sized" the cases to help with alignment and sealing, cases were clean except for the sized part.

Next I sent five of the same downrange but with 20 grains and a half-grain of Dacron, which packed pretty tight in there. I got a single, ragged hole with four and one almost touching, pretty sure I jerked that one. Again, a pinch of the yellow kernels and a slight wisp of black smoke curling in the barrel, but one try patch and the bore looked good as new.

My shoulder didn't complain too much, so I think I'll keep going up with the powder and down with the Dacron and see what happens. Looks like this might work out to be a gently compressed load with no filler or maybe a BP veggie disk right under the boolit if accuracy holds at longer ranges, only testing will tell. I'll set up the chronograph and some longer targets this weekend if I get time to load some more. Right now I need to cast some more and get them maturing, only about 20 boolits left.

Again, I appreciate the guidance, I don't like jumping in the water if I can't see the bottom!

Gear

[felix]

Sounds good, Gear. Leave the chrono at home until you get up to the recoil you can just tolerate for five rounds. If accuracy is satisfactory at that point, then permit the curiosity to win. I betcha' right now that 1300 or so for five will celebrate your bones enough. ... felix

[onondaga]

I believe the incomplete burn of powder kernels would disappear with substantially more compression of the BPI. The added volume with BPI will also act as a better gas check.

When you get any chronograph data you can do up velocity projections to determine charge by manipulating an inversion on this program:

http://www.handloads.com/calc/reduced.asp

The program is designed for reductions and does that easily, but can be manipulated for velocity increase.

Or, just PM me with a chronographed velocity and it's charge and I will do it for a velocity of your choice and calculate the charge to about +- .4 grains. This will give you a good projection of charge needed for velocity of your choice.





Gary

[felix]

Possible, Gary, but not likely because of the large expansion ratio. There is just not enough powder to create enough heat fast enough. But, that is the intent not to destroy the cases. Try and remember the force required to seat the primers after each cycle. When they become noticeably looser, drop the load back one increment as the final load arena. Brass just cost too much these days unless they are used to obtain something to eat as a trade. ... felix

[geargnasher]

Continuing the workup: 22 grains of RX7 with .5 Dacron, 23 with .5 (very tight), 24 with .3 Dacron. There is only about 1/8" space left in the case at 24, so that's why I'm not bothering with BPI at this point, and Dacron is too convenient. The advice on higher compression capability of the BPI is noted, I've used a bunch of it in bottlenecked cases to light slow powders and it WILL raise pressures and improve combustion considerably in those.

The barrel IS 20 inches, 19 from crown to base of boolit. This is a Classic Carbine with the checkered stocks, "fancy" walnut, case-colored receiver and buttplate, etc. My COAL is 1.840", and I can get 28.7 grains of RX7 in there at 100% density, but I doubt I'll make it that far, she's starting to buck. Not bad, no strawberries with only a tee-shirt, but it's starting to act like a real gun now instead of a shoulder-mounted pistol-boolit flinger.

The two with the orange stickers were from yesterday as described in post #13, I dated them wrong. All are five-shot groups at 25 yards because I'm short on time and can't see to my 50 yard backstop in the trees when the sun is low.

Gear

[onondaga]

You are doing the fun part now. Targets look great so far. Keep the news coming.

Gary

[leadman]

I had an older New Model Blackhawk in 45 Colt that had the typical large chambers and swelled brass badly. Chambers were different size also so could not just neck size.
I bought 454 brass and trimmed it down and this eleminated my brass issue.

I tried WC680 with the Lee 300gr boolit and ignition was poor even with a full case. Ended up using 24grs of H110 and got over 1,300fps, good accurracy, with a handful of recoil.

I have a few pieces of 460 S&W brass that I was playing with in a 45/410 Contender barrel if you want these to play with. Only have 4 or 5, couple have been shortened to extend the boolit closer to the rifling in the T/C.

[geargnasher]

Leadman, do yo have a case neck micrometer? I'd love to know how thick typical .460 brass is when cut back to .45 Colt dimensions.

Gear

[geargnasher]

Finally got to try something new, seems like I've going the wrong direction. My water-quenched 50/50 boolits ended up at 22 bhn after three weeks, so I sized them to .4545" for grins and loaded them on top of 24.5 grains of RX7 and .5cc BPI original filler. This is a pretty heavily compressed load.

I fired ten rounds for two, five-shot groups, first a little over two inches at 50 and the second a little under, both nice round groups. I recovered a few boolits that went clear through a two-foot long section Red Oak log lengthwise and bounced around through the lumber-rock-dirt riprap behind, the boolits stayed together, but TOO well. The only one that showed any expansion at all center-punched a crystalline-limestone rock after going through the log.

In spite of the decent groups, upon cleaning I found the barrel packed with lead from end to end. This is the first time this rifle has EVER taken on lead deposits, so I was a little miffed. Almost all of the lead pushed out with a tight patch and Ed's Red, 4-O steel wool got the rest

The recovered boolits had the lube grooves still full and no signs of gas-cutting. The bases were cupped quite a bit.

Back to the drawing board with alloy, I think I'll go for much softer next time, maybe cut this alloy in half again and water-quench.

Gear

[onondaga]

I think #2 alloy air cooled would do it for you because of the BPI filler.

The leading , I can't exactly figure. Leading from an alloy that is too hard or a barrel twist rate that is too fast for the bullet is usually shavings cut by the rifling. A coating that needs the work you put into getting out could be from a number of reasons that you know. You are close to the edge with something there causing the leading. But I bet you are real close to getting a smile.

Try minimal or no crimp also with the #2 alloy to protect your bullet diameter.

Gary

[MT Gianni]

This may not be the way you want to go, but those dimensions seem ideal for a try with FF or FFF .

[geargnasher]

MTG, that really IS a good recommendation, especially if I used air-cooled sticky weights and paper-patched (might do it yet), but not at all the way I'm trying to go here at the moment.

Gary, keep in mind that I'm looking for a short-range, fast-handling gun to hunt small, heavily-wooded acreage and am looking for the wonderful terminal effect of soft, large-caliber slugs here, even my 15-16 bhn ACWW didn't expand at all when hitting sand at the 25-grain mark.

The left five boolits were pulled from the 25 yard trap after firing some of the groups in the earlier pic, not certain which were which load, but all were with RX7 and in the same ballpark. Some were Dacron-filled and some were BPI. The three on the right were from this week fired thorugh the log, pretty tough trip after exiting, but I felt the alloy is way too hard for the velocity. Need softer boolits here. Softer boolits didn't lead, either.

Gear

[leadman]

I found for most of my shooting at moderate velocities, like 1,600 to 1,900 in 30-06, BHN 11 is hard enough with a good lube.
I use this in my 44, 41, 357 magnum also. I go just a little harder to 15 at 2,200 in my 30-30 and 30-30AI Contenders.

I use about 8 BHN in my 43 Mauser, 348gr boolit at 1,200 fps.

[felix]

Keep it up, Gear. My interest is peaked. ... felix

[geargnasher]

Time for an update. I've been busy on other projects, but I cast a pile of Lee 457-340-RFs about two months ago from a new mould, this time I used air-cooled 50/50 wheel weights/roofing lead for an aged hardness of 9 BHN. I tried a few the traditional way, sized .454" and .457", but got the leading again using more than 20 grains of RX 7.

So I decided to paper patch. Sized the boolits to .453" and then .448", patched to .457", lubed with Felix lube, and worked up again. I reached 24.2 grains with pretty heavy compression of the powder upon closing the action. Using fired unsized brass with .0015" total chamber neck clearance after seating the boolits, I get good engraving of the patch but the mechanical extractor still has no trouble extracting the round without debulleting. Here's the 50-yard, 10 shot group I submitted for the August PP postal match:

http://castboolits.gunloads.com/imagehosting/thum_89094e597bd333b83.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=1960)

When I get some more loaded I'll drag out the Chrony and see what they're clocking. The load leaves lots of unburned Kernels scattered down the bore, but the cases are clean inside and out and the recoil is quite tolerable, about like a .410 shotgun with 3" field loads.

I might still play with powder some, re-reading all the advice on this thread I keep coming to Gary's comments about trying one of the flavors of 4198. Might be worth a try, especially since this PP boolit seats deeper than before and the powder capacity is reduced a few grains.

I'll keep posting as I have new data,

Gear

[myfriendis410]

As I was reading this post I was going to suggest IMR 4198 and 4895 (if the former is still too fast). I'm using both in 500 grainers and getting good results. Another one to try is Benchrest. Comparable to 4895 but is a ball powder.

[geargnasher]

Ball powders get spooky when compressed sometimes, I'm trying to "stick" with stick powder :D for now, 4198 will get me the 100% density I need and not overpressure, so I'm going to try that first just to see what happens.

Gear

[405]

I use 5744 and Rel # 7 for loading at one end of my cast bullet burn rate scale and 2400 at the other end. If I need an even faster burning powder than 2400 for high expansion ratio, lower vel applications I use Trailboss. All of these powders seem very easy to light and have given me no surprises. I use Rel # 7 when high load density is not an issue. For the big straight wall cases where I want to duplicate as closely as possible black powder pressures and velocities I use mild charges of 5744 with dacron filler. I am unfamiliar with the "squirrely" cyclic pressure curve attributes of Rel # 7 as reported in this thread??. I have not noticed a need to use magnum primers for any of these powders and have noticed accuracy can fall off if magnum primers are used for certain loads. Also, I have avoided ball powders like the plague since the early 70s.

Oh and BTW, I think that the advice about leaving the chrono at home until your shoulder tells you something about pressure is bad advice! If you have a chrono when working up loads, by all means use it. It's the next best thing to having pressure equipment (that few of use have!). It is not foolproof but may show unexpected velocity thus pressure spikes.... a good thing to know.

[Old Goat Keeper]

Interesting read as I too have one of those 45 LC carbines. But I do have a question about something that it seems you all know! What does "BPI" stand for? Thanks in advance.

T-o-m

[onondaga]

BPI Original is a compressible plastic particulate commonly used as a buckshot filler in scattergun loads but is also recommended as a ballistic filler in reduced loads and it forms a quasi gas check for plain base cast boolits. My source:

http://www.midwayusa.com/viewProduct/?productNumber=695248

Gary

[felix]

The V-V powders are small cut single base powders. Not anywhere close to ball appearance, like H322 or 4227, really small cut single base tube powders. N120-N133 (4198) would be in the speed range of interest. Might be able to borrow enough from local BR guys/clubs for 5 rounds or so. All V-V powders burn MUCH cleaner than usual at 30K cup.

Best bet is to customize that chamber with a new barrel. But, for a 45 Colt? Must be in a diehard situation with nothing else on the plate except spare greens. ... felix

[geargnasher]

I did some more shooting this evening, fun little gun. Needed to empty a few odds and ends from the paper-patch experiments and see what the gun was like in a hunting situation. This little carbine is nimble, light, FAST on target, and packs quite a wallop for what it is, perfect for "walking up" whitetail in dense brush and rough country that we have here, and the PP soft boolits should keep tracking to a minimum, which was my new goal with this gun since I discovered the horrid chamber dimensions. I originally bought it as a compliment to my fleet of .45 Colt revolvers, even had a custom boolit mould made that I thought would work well in all of them as interchangeable ammunition, but alas the dimensional disasters that are most .45 Colt chambers pretty much forces a person to segregate brass, boolit, and load to each gun for best results.

Don't you wish stores would let you slug the chamber/throat before buying?

Gear

[felix]

You won't find a minimum chamber unless advertised as so, which would make chamber casting a waste of time because they are all too far gone. Do you think a smithy could make a business of rebarreling and come out worthwhile financially? Marlin and Winchester barrels of the popular lengths? ... felix

[w30wcf]

geargnasher,
I have used a capacity load of 28 grs of RL-7 under an RCBS 320 grain bullet in my Marlin 45 Colt Cowboy rifle with good results.
To get the powder to settle in the case, I dumped it slowly through the funnel from about 4-5" up.

I used a Federal 155 mag pistol primer and the average velocity was 1,416 f.p.s. in the 24" barrel.

The same charge of 4198 produced velocities that were 50 f.p.s. faster.

w30wcf

[Old Goat Keeper]

Enlighten me guys...what is "BPI?"

T-o-m

[onondaga]

Tom,
scroll back up the page and read response #32 .

Gary

[Old Goat Keeper]

Tom,
scroll back up the page and read response #32 .

Gary

OOPS! I was looking at the last new posts and missed it Gary. THANKS for explaining. Sure sounds like something MORE I need t get!

T-o-m who has a short memory any more

[geargnasher]

geargnasher,
I have used a capacity load of 28 grs of RL-7 under an RCBS 320 grain bullet in my Marlin 45 Colt Cowboy rifle with good results.
To get the powder to settle in the case, I dumped it slowly through the funnel from about 4-5" up.

I used a Federal 155 mag pistol primer and the average velocity was 1,416 f.p.s. in the 24" barrel.

The same charge of 4198 produced velocities that were 50 f.p.s. faster.

w30wcf

Wow, I'll bet that was a stomper load, on par with the 45/70 guide gun. I'm getting that you put in an equivalent volume of 4198 and it wasn't too much for the brass? I was a little apprehensive about the equivalent volume of 24 grains of RX7, but I'm looking for a cleaner burn and maybe just about 50 more fps than I'm getting. I chronographed five of the slightly compressed 24.2/RX7 paper-patched 340s and averaged just over 1300 fps.

Gear

[felix]

For S&Gs, use any of the 680s(H116 is one also), VV133 should give the same ball park velocities, but with different curves. If looking for slightly more speed, VV130 should be the ticket. Don't destroy your cases, though, and always check primer seating between reloading sessions. The bases do expand with these crazy chambers even though the pressure is low for the gun itself. Use full case loads as per this thread's intent. ... felix