Interesting thread, Marcus. I don't think I have the patience for all of the 'book-keeping' they did!

I spent most of the day wrestling this thing. In the end, I "won". I think. Unfortunately, since you usually don't know exactly what is wrong, you often end up 'fixing' one or more things that don't have anything to do with the problem. Such was the case today. However, all of those "extras" make the overall finished rifle that much better.

Fixing the 'scratchy' barrel-break lever wasn't a big mystery. The barrel 'lump' has a ledge that engages a latch (see part# 2 in the exploded view below), to lock the barrel closed - "in battery". (The 'ledge' is right above and slightly right of the number "9" in the schematic, at the bottom of the barrel lump.) Since this barrel (the H&R stub part), didn't come from the factory with this receiver, I had to file that ledge a little to get the barrel to lock-up in this receiver. (I did that as soon as I got the barrel.) Since the headspace was "tight" (the head of the case was about 0.0015" proud of the breech of the stub), when the barrel was closed on a cartridge it was "tight". This changed the fit of the 'ledge' to the 'latch'. That is what made the barrel-break lever scratchy. I file a few more thou' off of the ledge and all of the scratchiness is gone. Now, a 'perfect' fit between ledge and latch.

Since the ejector I purchased to replace the 12 gauge ejector that came with the 12 gauge barrel, was for a 45-70 Gov't, it was just ever so slightly 'out of spec' for the .348 cartridge head and rim. It was binding just a little when the barrel was closed on a loaded (dummy) cartridge. Now it's 'perfect'.

As I said, the headspace was a little "tight". After a LOT (about 4 hours) of fiddling, it became clear that I had to deepen the chamber ever so slightly. About 0.0035". That's not much, but it made all the difference. Before I cut the chamber that much deeper, cartridges would stick in the barrel. (Not eject.) After, they shoot right out. Now the head of the cartridge is about 0.0015" "in" the chamber. In other words, instead of being 'proud' of the chamber by 0.0015" it is now 'recessed' by about 0.0015". Using the dummy round.

The final 'issue' was the trigger returning to its forward-most position after firing and releasing it.

If you look at the parts circled in red, you will see the trigger (part# 29) and the trigger return spring (part# 34). The spring sits in a recess made for it in the plastic trigger guard (part# 31), but there is no "place" for the other end of the spring to fit "in" the trigger (part# 29). It just rests against that curved face of the trigger below the sear. The spring is supposed to 'slide' up and down that trigger face. Unh hunh. But it doesn't... much. I lubed it, and that helped. Maybe I'll have to get a new spring. It 'returns' most of the time now.

In the midst of working on the chamber, I was trying to get the exact chamber length to enter into QL so I could get the most accurate estimates of velocity and pressure out. I got tired of 'flatulating' around and did two things:
1) I made a chamber gauge to measure chamber length. It's just a rod with the forward end slightly larger than the BORE diameter: 0.409" in this rifle's case. The gauge is cut to 0.4105". When dropped in the chamber, it 'bottoms out' on the front of the chamber where a bullet will hit. Subtracting the amount of the gauge that protrudes from the breach from the length of the gauge yields the precise chamber length. The ogive of a bullet with diameter 0.4105" cannot be loaded "out" farther than that length without pushing the bullet into the lands. I have found that somewhere about 0.050" BACK of that point is more often than not a precision "sweet spot". That's where I will start with QL. (More on that later.)
2) I also made a Lock-N-Load (used to be Stoney Point) case. This case has the neck enlarged so that a bullet of the appropriate caliber (.416 in this case), slips in and out of the neck easily. (I made the mouth 0.424" in diameter.) Also, the head is drilled and tapped 5/16-36. This matches the Lock-N-Load tool thread. To use this tool you put  the bullet you want to use in the case mouth and screw the tool into the head of the case. Then insert the case into the chamber and push a rod through the tool to 'seat' the bullet against the lands. Once the bullet is seated, you lock the rod in place and retract the cartridge. Given that the rod is against the base of the bullet, you have the max length your cartridge can be FOR THAT BULLET.

The gauge performs the same function, but not very many people have access to a lathe to make the gauge.

Having 'fixed' everything, I set about calculating starting loads for all the bullets. That lead to an inescapable conclusion: I have to get a .416 throating reamer. This reamer cuts a throat that is fine for 350-grain bullets, but not for 400 and 500-grain bullets. Those heavier bullets have to be seated too deep, which increases pressure above where I want to be - less than 32,000 PSI. The 500-grain Hawk bullet has to be seated 0.821" deep with this chamber. Nevertheless, the chamber is fine for the Speer and Hawk 350-grain bullets. The pressures for those bullets at 1900 f/s MV are all under 28,000 PSI.

So, in conclusion: Everything that was wrong MIGHT be fixed. (I haven't test-fired it after the 'fixes'.) I have what appear to be pretty good loads (in the context of pressure and velocity) for the 350-grain bullets. I'll put up a target, test-fire it this evening, and report the results 'later'.

Paul

PS - I should probably clarify that 'head-space', per se, wasn't the problem with the cases sticking. The problem was that this reamer cuts chambers very close to the size that the resizing die resizes to. Therefore, since the chamber wasn't 'deep' enough, the wall of the cartridge was 'grabbing' about the last 16th of an inch. (Don't need to go 1/16th of an inch IN to get the WIDTH a few thou' wider.) Just wanted to make sure no one was thinking that I was saying that 0.0015" of headspace 'tightness' could cause 'sticking' cases.

Paul

That didn't take long.



Just:
1) A 'quick & dirty' function test,
2) First shots 'on target', and
3) Check out load.

Range was 25 yards. The first shot was the upper one. The second shot I aimed as low of the bullseye as the first one was high. The 'red dot' is the second shot moved up as if it had been shot with the same point of aim as the first.

The MVs were 1863 and 1860 f/s respectively. At least they weren't high. They're low by 37 and 40 f/s respectively.  (Predicted was 1900 f/s.)

Recoil was brutal. Gotta do something about that.

Both rounds fired with only one pull of the trigger each.

Both cartridges ejected perfectly.

The corners of the shoulder are nice and sharp.

Overall, pretty pleased. Wooduh liked it better if it had been like this the first time I pulled the trigger.

Next up is getting a new batch of bluing liquor made up. Then some range time to get sights "on". Looks like windage is close. Going to have to shoot some more to see how precision is.

Between Vihtavouri powder and spendy bullets, it costs 'money' to pull the trigger on this one. VV powder is $42/lb or 0.6 cents per grain. 50 grains is therefore 30 cents. The Speer 350 is 73 cents per bullet (including shipping to me), the primers are something like 2 cents a piece, and I won't count the brass as that's too much to amortize in this thread. So, every pull of the trigger costs about $1.05. Not horrible, but I'm used to paying less than half that for "smaller" cartridges. Good thing I'm not getting them custom loaded. I'm going to get a pound of I4831.

I'll update when there's something new to add.

Paul

https://www.reamerrentals.com/ProductDetails.asp?ProductCode=416%2Et

:D

Also, I was able to find some tungsten cobalt carbide "sand" for about 10X the price of lead. Good thing I don't need much.

Paul

The tungsten cobalt carbide 'sand' came in the mail yesterday. They gave me a little more than 2 lbs. :)

The rifle as is, weighs 7 lb 1 oz. I haven't got the 'sand' in the butt yet, but assuming I can only get exactly two pounds of it in, the new weight will be 9 lb 1 oz. Here are some numbers showing the difference in recoil.



I have circled in red the values that are different. Of course, these don't take into consideration 'stock design' or 'fit'. That's irrelevant to the comparison because it's the same rifle with the same 'design' and 'fit'. Therefore, comparing different weights is apples-to-apples. The number I care most about is "Energy of recoiling mass". That 35 ft-lb of 'recoil' is 'brutal' in that stock. The 27 ft-lb from the 9-lb version will be a BIG difference. I am also going to put a recoil pad on it. That will both add some weight, and 'soften' the blow.

You can see the difference a couple of pounds makes! Two pounds is a 28.5% increase in weight. All of the numbers associated with recoil are 28.5% "better" in the 9-lb gun. Of course there are 'trade-offs'. One is increased weight to carry around. Most of 'you' will know that I don't give a hoot about rifle weight until it gets over 11 lb. The second trade-off is 'balance'. We'll have to wait and see if the added weight to the butt makes this rifle 'butt-heavy'. I don't THINK it will, but it may. If it does, that will be a price I will have to pay for reduced recoil.

Paul

PS - There is another number I note that might be of significance: "Gun Travel". That's how much the gun has moved from the moment the trigger was pulled, to the  moment when the bullet leaves the muzzle. In the 7-lb weight, the value is 0.173 inches. In the 9-lb weight, the value is 0.135 inches. That 0.038" of movement will have SOME affect on point of impact, and the farther out, the greater the impact.

Paul

From an earlier post in this thread:

QuoteFinished rifle weighs 7 lb 2 oz. Not enough. Gonna hafta put some lead in its butt. Get another pound in at least if I can. According to my calculations and based on a density of 436 lb per cubic foot of #8 lead shot, (https://marsmetal.com/lead-shot/), I can get 18 ounces of #8 lead shot in the butt - a pound and two ounces. That would bring the total weight up to 8 lb 4 ounces. Without getting 'crazy', that's about the max I can get the weight. That's an increase of 14%. Not great, but better than a poke in the eye with a stick. Or a thump in the face with a gun stock.

Y'all may recall that I purchased some tungsten shot/"sand". I finally got around to getting it in the bolt hole in the butt. Here are some pictures.

Here's the whole tube:

This is standard 3/4" copper tubing. Turns out to fit PERFECTLY in the bolt hole.

Here are a couple of pictures of the ends:

This is the 'distal' or end near the buttplate.


This is the 'proximal' or end near the bolt head.

I made these plugs 1/8" thick and a 'pressure' fit. I put (lightly hammered) the proximal end plug in, filled the tube with very tiny tungsten 'shot', and put the distal end cap in. I put a little bit of tissue paper over the bolt head, and a little bit over between the tube and the buttplate.

And here it is "in situ":


Total weight of the tube is 1 pound 10 ounces. Since the original weight of the rifle was 7 pounds 2 ounces, the final weight of the rifle is now 8 pounds 10 ounces. That's an increase of 21%. Calculated recoil is reduced from 48 ft-lb to 39 ft-lb. A reduction of 23%. I can tell you from first-hand experience that reducing recoil by about a quarter is SIGNIFICANT. Also, the rifle now balances about half an inch behind the barrel hinge pin. That's VERY close to 'right in the middle'.

SO... I think this will be "good".

Paul

I don't think I mentioned this. The throat on the .416x348 Win reamer is a little short for the Hawk 400 bullet, so I bought a .416 throater from Manson. It didn't take longer than 10 minutes to lengthen the throat perfectly so that the Hawk 400-grain bullet, when seated 1 caliber deep, is ~0.05" (50 thou) off the lands. The 350s (Speer and Hornady) are about 50 thou off when seated 2/3rds of a caliber deep (.278"). The 500-grain Hawk will be a little 'deep' (I don't recall the exact number right now), but I don't expect to be shooting that bullet too often. That 50 thou off for the 400 MAY have contributed to the precision of those first shots.

Paul