H&R in 450 Marlin

[brad925]

Am wondering if there is anywhere i can get reloading info on this cartridge.

[stubert]

http://stevespages.com/page8a.htm

[BABore]

Hodgdon and Alliant have on line data for the Marlin 1895 action which is rated at 42,500 psi. Lyman and a few other popular manuals also have data listed. My preference is Reloder 7 for 300-350 grain boolits and IMR 3031, H322, and Benchmark for the 350-450 grain boolits. H335 and IMR 8208 is good for the real heavies. CCI 200 primers are a good standard primer and Federal 210M match primers for serious accuracy.

[clintsfolly]

My 450mar in a Savage110 24" 1/20twist shoots great with 457122/aa2300 Clint

[tommygirlMT]

The 450 Marlin is the same as a 45-70 only with a belted instead of rimmed base and loaded to higher pressure levels

THUS --- you can use 45-70 load data to load 450 Marlin

45-70 Data is all over the place and very accessible --- usually 45-70 loads come in three variations --- trap door pressure level lads --- heavy Ruger and Marlin Loads --- and Modern Bolt action only loads (50,000+ pressure) --- You may use to two lower levels of the 45-70 data to load for 450 Marlin --- don't use the top bracket loads since you will technically be over pressure although I'd be willing to bet that the H&R single shot could handle those loads since they chamber it in higher pressure rifle cartridges with he same frame

[Bowen4]

RanchDog has some stuff under .460-425 mold. Marlin Owners!

[wallacem]

I can attest that the H&R will shoot the top power lever 45/70 loads, but my shoulder did not like them a bit. Since that one time I have stuck to trapdoor loads. Don't need anything stronger. Have not found a single elephant running around the woods in Georgia. Wallacem

[dk17hmr]

I had a 16.5" NEF 45-70 that I would load up with level 3 stuff, was fun for a couple rounds, than back down to level 2. I just used RanchDogs load data for the 450 Marlin Handi Rifle I had, it shot great with his 425gr design.

[BABore]

The 450 Marlin is the same as a 45-70 only with a belted instead of rimmed base and loaded to higher pressure levels

THUS --- you can use 45-70 load data to load 450 Marlin

45-70 Data is all over the place and very accessible --- usually 45-70 loads come in three variations --- trap door pressure level lads --- heavy Ruger and Marlin Loads --- and Modern Bolt action only loads (50,000+ pressure) --- You may use to two lower levels of the 45-70 data to load for 450 Marlin --- don't use the top bracket loads since you will technically be over pressure although I'd be willing to bet that the H&R single shot could handle those loads since they chamber it in higher pressure rifle cartridges with he same frame

Do not ever use 45-70 data for the 450 Marlin!

There is over a 7 grain case volume difference between Winchester 45-70 brass and Hornady 450 Marlin brass. A top end, level II, 45-70 load worked up in Winchester brass would take you well into and likely over level III pressure levels if stuffed into a 450 Marlin case. A fools errand.

[tommygirlMT]

Well --- I found BABore's assertion that the 450 Marlin has slightly less internal case capacity then the 45-70 very intregin --- BABore usually knows what he is talking about and I respect his knowledge but at the same time I've read that you can use 45-70 loads in the 450 Marlin and the Lee book lists both cartridges as having the exact same useful case capacity of 4.06ccc --- and I have been doing this kind of load swapping for a long time in both my BFR revolver (Level 1 & 2 loads and loads listed for contender pistols) and a semi-custom bolt rifle I have which is a belted magnum action rebarreled for the 450 Marlin with a flutted 21" bull barrel (Level 1 & 2 & 3 loads)

So I got out some assorted head stamp 45-70 cases and some 450 Marlin cases and sized them in their appropriate full length sizing die and then trimmed them all to exactly 2.100" length --- I then used some surplus fine ball powder to fill them all to the brim nice and level with the top wipped flat with a credit card

Long story short --- BABore is right with on average the 45-70 cases holding about 0.3cc more volume then the 450 Marlin cases with the largest difference I found being about 0.4cc

At this point I was wondering why my load swapping habit hadn't been giving me loads that were showing pressure signs --- then I realized that I always seat the boolit just deap enough enough to just kiss the beginning of the rifling on the rifle and use that same seating depth if not even less for loads in the BFR and this usually means I am leaving the top groove without lube and crimping on the drive band below the top lube groove instead of in the crimp groove (if there is one on the booolit) --- I pulled an assortment of my loaded rounds out of storage and checked the over all length and they are significantly longer then the over all lengths called for for either the 450 Marlin or 45-70

Then I did some math and with a 0.358" boolit dameter --- 0.15" less seating depth (or longer over all length which ever way want to look at) increases powder area volume by 0.405cc and most of us are using cast boolits a little bigger diameter then that so it is more like 0.41cc

IN CONCLUSION --- Swapping in 45-70 load data is still safe and sane IF you reduce boolit seating depth by at least 0.15" --- that will make up for the difference in case capacity --- obviously check what th minimum cartridge over all length is listed with the load you are using and add 0.15" to that since not all loads call for the same minimum cartridge over all length --- this may also mean that such loads would not cycle through a lever action --- work fine with my bolt gun though and I dont see any problem with single shot break action

P.S. --- all my loads were worked up from the start load in 450 brass --- I just don't go shove a load I worked up in 45-70 brass into the Marlin brass without going back to the start load --- shouldnt ever load more then the start load to begin with without working up even if you were just going from one gun to another chambered for same exact cartridge