10.75x52r Grundig-Scruggs update

[sakorick]

Now that I know what it is I thought we could shift gears to the loading and shooting phase of my new Dreiling with a dedicated thread. To date, I have cast the bore, fireformed the brass, received the dies from CH-4D and obtained a wonderful array of bullets from my friend Paul in AK. Paul has a lot of experience with these guns and has two different calibers he has loaded and fired for years. I will be working with 3 bullets resized to .425 with custom dies and two powders to wit(all loads based on QuickLoad estimates and Paul's experience):

1. 317 gr Lee C430-310-RF w/ gas check. Seat 0.535, COAL 2.373, 46.8 gr Acc 2495, CP 24,500 PSI, MV 1961 f/s, ME 2706 ft-lbs
2. 257 gr Lyman LFN w/ gas check. Seat 0.755, COAL 2.447, 52.3 gr Acc 2495, CP 22,381 PSI, MV 2143 f/s, ME 2622 ft-lbs
2. 243 gr Lee C429-240-RF w/ gas check HP. Seat 0.438, COAL 2.369, 36.5 gr Hodgdon Lil Gun, CP 28,500 PSI, MV 2202 f/s, ME 2618 ft-lbs

Accurate 2495 comes UPS from Powder Valley tomorrow and the shooting/range report follows.

[sharps4590]

Go get 'em rick!!! Can't wait to see your results!

[mike ford]

Rick,
Great, if you are not satisfied, we have good luck with 5744. Have fun and let us know how it goes.
Mike

[sakorick]

Quick load is used only as a guide not the end all. In this case I was interested in low pressure combined with decent speed. With QL you can set parameters which then searches the data base for possible combinations. Once you pick a candidate further analysis reveals things like rapid pressure spikes associated with minimal powder charge increases. I am still a novice with the software, however, the software is very useful.....especially for odd ball cartridges like the Grundig-Scruggs.

[mike ford]

Sakorick,
I am interested in the "Scruggs" part of the cartridge, would you mind describing where it came from? The 10.75x52R Grundig is a straight tapered case, whereas your fireformed case has necked form with a visible shoulder,reminiscent of the 10.75R Springer(which has the same head dia.). I couldn't find reference to Scruggs in my paltry data sources. Is this part of a series,with different calibers,or a "one off" caliber?.( I always say, it doesn't matter what you call a cartridge as long as you can find or make cases/bullets/and dies, for it).
Mike

[Axel E]

Sorry, but your drilling is not chambered for any variant of the Gründig cartridges at all, as you were able to make cases from 7x65R. The G = Gründig series of cartridges have a base diameter of 12.48 mm = .491", .025" larger than a 7x65R with 11.85 mm = .466".
Instead, your Drilling seems to be chambered for a variant of the LK series of cartridges. These were black powder, lead bullet cartridges, popular for drilling use before 1905. In fact, old catalogs call them "11 mm Drillingspatrone" = drilling cartridge or "Drillinghülse" = drilling case. The LK series also came in lengths of 40, 50, 52, 55, 60 and 65 mm. All have a base diameter of 11.9 mm = .469", your "only about four thousands" off the 7x65R. At the time your drilling was made, nothing was standardized. Barrels for lead bullets were often made very tight, relying on the soft bullets swaging down on firing. And, gunmakers often designed their own, just slightly different wildcats or proprietary cartridges, ensuring that their customers would come back to buy the proper ammo.
So drop the "Gründig" monicker from your cartridge name. "Scruggs Drilling Cartridge" would be a more apprpriate name.
BTW, your photo above Shows the case with a distinctive neck, not typical for neither Gründig nor LK cartridges. The photo of your chamber casts in your first thread show no neck at all. Is that Neck an optical illusion, a result of sizing the neck down to hold a smaller bullet?

[mike ford]

Axel,
I missed that he was using 7x65R cases.The only way I can understand that, is I must have gone directly from page 1 on his other thread directly to page 3 or didn't" refresh". I feel foolish that I told him I was confused(in a comment on page 3)becaues he reported a .465" head dia. but said it was for sure the Grundig and they have drastically different head diameters.I should have corrected him then, but missed it. BTY the LK cases in Dixon didn't show a neck, because they are all 11.15 mm.
Mike

[sakorick]

Sorry, but your drilling is not chambered for any variant of the Gründig cartridges at all, as you were able to make cases from 7x65R. The G = Gründig series of cartridges have a base diameter of 12.48 mm = .491", .025" larger than a 7x65R with 11.85 mm = .466".
Instead, your Drilling seems to be chambered for a variant of the LK series of cartridges. These were black powder, lead bullet cartridges, popular for drilling use before 1905. In fact, old catalogs call them "11 mm Drillingspatrone" = drilling cartridge or "Drillinghülse" = drilling case. The LK series also came in lengths of 40, 50, 52, 55, 60 and 65 mm. All have a base diameter of 11.9 mm = .469", your "only about four thousands" off the 7x65R. At the time your drilling was made, nothing was standardized. Barrels for lead bullets were often made very tight, relying on the soft bullets swaging down on firing. And, gunmakers often designed their own, just slightly different wildcats or proprietary cartridges, ensuring that their customers would come back to buy the proper ammo.
So drop the "Gründig" monicker from your cartridge name. "Scruggs Drilling Cartridge" would be a more apprpriate name.
BTW, your photo above Shows the case with a distinctive neck, not typical for neither Gründig nor LK cartridges. The photo of your chamber casts in your first thread show no neck at all. Is that Neck an optical illusion, a result of sizing the neck down to hold a smaller bullet?

Yes, it doesn't show well in the cast picture but there is a tiny distinctive neck demarcation that that gradually shrinks down. At any rate it shoots great. The 317 grain bullets were a bit spastic, however the 257gr bullets with the Acc 2495 were sensational with 52.1 grains of powder. I agree it's not a Grundig case, however the resize dies gets the correct neck size and the COAL seems perfect. There were no pressure signs on the case, no primer crater and they extracted easily with the flick of a fingernail. Scruggs Drilling Cartridge is what I will call it. I learned a lesson shooting the big bullet through the chrony offhand......be careful to wrap you thumb around the tang.....there are lots of things up there to whack your thumb! 257 grain bullet chronied at 1950'/sec....This can be made quicker no doubt. Here is the range photo from this afternoon practice.

[sakorick]

I remeasured the cast and there is no taper in the chamber. They must have shot larger diameter bullets that were swaged down on firing as Axel described. That said, the Grundig resizing die does a perfect job of getting the neck to .424 and I'm not showing any pressure signs. I will be shooting the 243 grain bullet and have made a temporary plastic front sight which is under testing now.

[mike ford]

Rick,
Since that is the case, you might try .429-.431"dia. 44 cal pistol or 444 Marlin bullets. Cast bullets of 260 grains are common and heavier are avaliable. This might cause the gun to shoot a little differently, and it's pretty hard to argue with your 100 yard groups.Using cast bullets would allow a lot more shooting, which is a good thing.Just for information, what size bullet will fit into the neck of a fired case?
Mike

[mike ford]

Axel,
Dixon shows a bullet diameter of 11.2mm(.441") for the 11.15x52 LK Express, in your experience have you seen one chambered in a barrel as tight as .423-4"? Could Ricks rifle really be intended for 11.15x52R LK ammo?
Mike

[Axel E]

Yes, I think it possible. Dixon may have measured the oversize driving/seating stop band the German lead bullets featured.
As I wrote before, nothing was standardized about 1900! Every gunmaker built his barrels to his own ideas as to dimensions, often tailoring them to use a specific bullet and load. As there was a strong belief that tighter barrels shot better, you often encounter barrels that are greatly undersize by today’s standards. This habit continued up to WW1. I have slugged Suhl made 8x57IR barrels, meant to used .318” steel jacketed bullets, with groove diameters as small as .315”. As they stood the proof load, they were deemed ok.
On the other hand factory swaged lead bullets were available in a bewildering variety of shapes, weights and diameters. As the bp cartridges were often loaded by the gunsmith who sold the gun, the loads were often tailored to fit a specific gun. Here are just two pages from a pre-1910 RWS bullet catalog that show some bullets in the .400 to .450” range:

A x52 LK cartridge from my collection is loaded with the 68A, .434" bullet.

[sakorick]

Sorry for my tardiness. I have settled with the 257 grain bullet. It simply shoots straighter. I also built a front sight that I can see. I am ready for deer season and have supreme confidence in the rifle. I also have pattered the shotgun and it will go to South Dakota on this year's Pheasant hunt. Our spot in NC Kansas that we have been hunting for nearly 40 years just no longer has a population worth damaging. My relatives and friends are all on a waiting list to bag a Rooster with the Dreiling. I'll fuss with the hammer screws this Winter when I have lots of time.

[mike ford]

Sakorick,
Great, good luck this season.
Mike

[old colonel]

Possibly a Springer 10.75x52r

In looking at pictures of your case with shoulder and the head diameter question noted it is possible your cartridge maybe 10.75x52r Springer. I own double rifles in both the 10.75x52r grundig and 10.75x52r Springer. The fire formed cases from my 10.75x52r Springer look identical to your pic.

Like you I used Quickload to derive data. I describe my process here: http://www.doublegunshop.com/forums/...=331364&page=1
And
http://www.doublegunshop.com/forums/...=321400&page=1

Pictures of the chamber cast are here, note, the case shown is not fired formed which have less shoulder, but was formed in a press with Ch4D springer dies: http://www.picturetrail.com/sfx/album/view/24335437

The 10.75x52r Grundig has no shoulder whatsoever. I have original grundig rounds (brought for $27 each on grunbroker) and they chamber in my grundig but not in my springer

I note that both the 45.70 gov brass and the 8x56r hungarian work for my springer, but not my grundig.