457 WW performance

[efremtags]

Anyone have experience with this conversion.

I have a guide gun and could not justify the mod on such a short barallel, but on a 22-24" barallel, it may make sense. I was thinking a 250GR TSX load at 2400FPS may be feasible in the longer tube, and would give the 338WM a run for its money out to 300 yards. It may also provide useful velocity on heavy 540GR cast ammo. I was thinking the new XLR would be perfect to convert as it is SS with laminated stock. With low power scope it is a lot of power in an 8.5lb package.

I have WWG sites and trigger and am very happy with them. Should I buy a used 45/70 and get it converted.

[quickdtoo]

The poor .136 BC of the 250gr TSX would make it a poor performer against the same weight bullet from the 338WM. The 300gr TSX at .163 would be a better choice, although the 200gr Nosler PP with a BC of .199 can be pushed to 2400fps in a 22" 45-70 barrel. But none will hold a candle to the 338WM at 300yds and beyond.

Tim

http://www.barnesbullets.com/products/rifle/tsx-bullet/

Trajectory for Custom .458 Barnes 250gr TSX at 2400 Feet per Second
At an Elevation Angle of: 0 degrees
Ballistic Coefficients of: 0.136   0.136   0.136   0.136   0.136
Velocity Boundaries (Feet per Second) of: 2400   2400   2400   2400
Wind Direction is: 0.0 o'clock and a Wind Velocity of: 0.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0   Cross Range: 0.0   Vertical: 0.0
Altitude: 500 Feet with a Standard Atmospheric Model.
Temperature: 59 F
Data Printed in English Units
Range   Velocity   Energy   Momentum   Drop   Bullet Path   Wind Drift   Time of Flight
(Yards)   (Ft/Sec)   (Ft/Lbs)   (Lb-Sec)   (inches)   (inches)   (inches)   (Seconds)
0   2400.0   3196.9   2.66   0.0   -1.5   0.0   0.000000000
25   2249.5   2808.4   2.50   -0.2   0.73   0.0   0.032279377
50   2104.3   2457.6   2.34   -0.82   2.54   0.0   0.066752448
75   1964.6   2142.1   2.18   -1.94   3.85   0.0   0.103641299
100   1830.7   1860.1   2.03   -3.62   4.6   0.0   0.143191495
125   1703.1   1609.9   1.89   -5.95   4.7   0.0   0.185670896
150   1582.7   1390.3   1.76   -9.04   4.05   0.0   0.231359268
175   1470.3   1199.9   1.63   -12.99   2.53   0.0   0.280535914
200   1367.0   1037.1   1.52   -17.94   0.0   0.0   0.333456936
225   1274.0   900.8   1.41   -24.06   -3.69   0.0   0.390318751
250   1192.7   789.5   1.32   -31.52   -8.72   0.0   0.451205355
275   1124.3   701.6   1.25   -40.51   -15.27   0.0   0.516026733
300   1068.6   633.7   1.19   -51.21   -23.55   0.0   0.584513305


Trajectory for Custom .458 300gr Nosler PP at 2400 Feet per Second
At an Elevation Angle of: 0 degrees
Ballistic Coefficients of: 0.199   0.199   0.199   0.199   0.199
Velocity Boundaries (Feet per Second) of: 2400   2400   2400   2400
Wind Direction is: 0.0 o'clock and a Wind Velocity of: 0.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0   Cross Range: 0.0   Vertical: 0.0
Altitude: 500 Feet with a Standard Atmospheric Model.
Temperature: 59 F
Data Printed in English Units
Range   Velocity   Energy   Momentum   Drop   Bullet Path   Wind Drift   Time of Flight
(Yards)   (Ft/Sec)   (Ft/Lbs)   (Lb-Sec)   (inches)   (inches)   (inches)   (Seconds)
0   2400.0   3836.3   3.20   0.0   -1.5   0.0   0.000000000
25   2296.5   3512.6   3.06   -0.19   0.45   0.0   0.031946564
50   2195.6   3210.6   2.92   -0.8   1.98   0.0   0.065347082
75   2097.1   2929.0   2.79   -1.86   3.06   0.0   0.100299879
100   2001.2   2667.3   2.67   -3.41   3.65   0.0   0.136911060
125   1908.0   2424.6   2.54   -5.5   3.7   0.0   0.175294007
150   1817.6   2200.2   2.42   -8.19   3.14   0.0   0.215569923
175   1730.1   1993.6   2.30   -11.54   1.94   0.0   0.257866354
200   1645.9   1804.3   2.19   -15.62   0.0   0.0   0.302314254
225   1565.3   1631.8   2.08   -20.5   -2.74   0.0   0.349045328
250   1488.4   1475.4   1.98   -26.26   -6.36   0.0   0.398189404
275   1415.6   1334.7   1.89   -33.01   -10.97   0.0   0.449867059
300   1347.4   1209.2   1.79   -40.84   -16.66   0.0   0.504182856



Trajectory Variations for Custom .338 Barnes 250gr TSX at 2600 Feet per Second
At an Elevation Angle of: 0 degrees
Ballistic Coefficients of: 0.425   0.425   0.425   0.425   0.425
Velocity Boundaries (Feet per Second) of: 2600   2600   2600   2600
Wind Direction is: 0.00 o'clock and a Wind Velocity of: 0.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0   Cross Range: 0.0   Vertical: 0.0
Altitude: 500 Feet with a Standard Atmospheric Model.
Temperature: 59 F
Data Printed in English Units
Range   Velocity   Energy   Momentum   Drop   Bullet Path   B.P. Diff   Wind Drift
(Yards)   (Ft/Sec)   (Ft/Lbs)   (Lb-Sec)   (inches)   (inches)   (inches)   (Inches)
0   2600.0   3751.9   2.89   0.0   -1.5   0   0.0
25   2549.0   3606.2   2.83   -0.16   -0.04   0   0.0
50   2498.6   3465.0   2.77   -0.66   1.08   0   0.0
75   2448.7   3328.0   2.72   -1.5   1.86   0   0.0
100   2399.4   3195.2   2.66   -2.71   2.28   0   0.0
125   2350.6   3066.7   2.61   -4.3   2.31   0   0.0
150   2302.4   2942.2   2.56   -6.27   1.96   0   0.0
175   2254.8   2821.7   2.50   -8.66   1.19   0   0.0
200   2207.7   2705.1   2.45   -11.48   0.0   0   0.0
225   2161.1   2592.1   2.40   -14.74   -1.64   0   0.0
250   2115.1   2482.9   2.35   -18.46   -3.74   0   0.0
275   2069.6   2377.4   2.30   -22.67   -6.33   0   0.0
300   2024.8   2275.4   2.25   -27.39   -9.43   0   0.0
325   1980.5   2176.9   2.20   -32.64   -13.05   0   0.0
350   1936.8   2081.9   2.15   -38.44   -17.23   0   0.0
375   1893.6   1990.2   2.10   -44.82   -21.99   0   0.0
400   1851.2   1901.9   2.05   -51.81   -27.35   0   0.0

[efremtags]

Thanks for taking the time to plot the data.

based on the nosler 300gr, you have a very usable trajectory out to 300 yards. I agree 45 cal will never match ballistics of 338, but the point is more that the 457, 45/70 could be a 300yard guin, not just a brush gun.

[EsoxLucius]

The Wild West Guns 457 Magnum is a superfluous cartridge as one can get the same performance with a 45-70 by modifying the Marlin 1895 to cycle 2.67" rounds.

[efremtags]

ESOX,

could you recommend a good Gun smith that does this. I have heard mixed reviews about WWG services as customer service has been mixed. I had no problem buying parts, but shiping my gun off for 3 months is a different story.

[EsoxLucius]

Mic McPherson

David Clements

David Clay

Cosby's Custom Gunsmithing

Bozeman Trail Arms, Mfg.


Any competent gunsmith should be able to do the work as described in Mic McPherson's article Maximizing Marlin's New Model - 1895  in the October 1998 issue of Precision Shooting magazine.  I had a local gunsmith do mine.  I talked to him about it and he said he wanted to try it.  I just gave him the magazine article and he did a fine job.  I can now cycle and chamber 2.67" rounds, although I usually just use 2.55" rounds anyways.

[efremtags]

Does having a longer chamber ruin accuracy of the standard SAMMI length rounds. I have read about contender's having sloppy tolerances in this regards and the fix is to ream chamber for longer cartridge.

My current gun is very accurate and I would hate to loose this for 100fps. Any experience with this.

[EsoxLucius]

The chamber is not lengthened in the modification to a Marlin 1895 45-70 to cycle a longer round.  The length of the throat is sufficient to accommodate virtually all bullets seated to 2.7".

The WWG 457 Magnum requires reaming the chamber about 0.1" to accommodate the longer brass only.  It shouldn't really affect accuracy much if at all shooting a 45-70 round in the WWG 457 Magnum.

[S.B.]

This conversion sounds interesting?

[S.B.]

The chamber is not lengthened in the modification to a Marlin 1895 45-70 to cycle a longer round.  The length of the throat is sufficient to accommodate virtually all bullets seated to 2.7".

The WWG 457 Magnum requires reaming the chamber about 0.1" to accommodate the longer brass only.  It shouldn't really affect accuracy much if at all shooting a 45-70 round in the WWG 457 Magnum.

Please pardon my ignorance but, you first say the chamber is not lengthened but then say the WWG .457 chamber requires reaming the chamber by 0.1" Which is it???   Did you mean to say the barrel lead is reamed 0.1"? What other modifications are required for this conversion, opening the ejection port?

[EsoxLucius]

The issue with a cartridge overall length over 2.55" in the Marlin 1895 45-70 (some 1895s allow a slightly longer COL depending on the bullet nose configuration) is not that the round cannot be chambered, but that it cannot be cycled from the magazine into the chamber.  Hence, a modification to the cartridge carrier, ejector, bolt face, frame opening above the tubular magazine port and below the bottom center of the chamber opening, and barrel opening at the side of the chamber near the extractor cut area allows the cycling of longer rounds from the magazine to the chamber. 

There are two different issues here.

1. The WWG 457 Magnum conversion, which requires running a reamer in the Marlin 1895 45-70 chamber to allow for a cartridge that has a 0.1" longer case.  The throat of a Marlin 1895 45-70 is long enough that virtually all bullets can be seated to a 2.7" cartridge overall length before contacting the lands, so the throat is untouched.  Then the action is modified to cycle longer rounds.  Cartridge overall lengths for the WWG 457 Magnum are typically not more than 2.67".

2. The Marlin 1895 45-70 with only the action modified to cycle a longer 45-70 round with 45-70 brass.  The Marlin 1895 45-70 can be modified to cycle rounds up to 2.73", with increasing difficulty in the process when striving for more than 2.67".

However, with both you get to the same place.  A longer round provides more effective case capacity and slightly increased velocity.  But the WWG 457 Magnum does it with a ream job, expensive brass that is 0.1" longer than 45-70 brass and the modification to the action to cycle the longer round, while when keeping the rifle a 45-70 just the modification to the action of the Marlin 1895 45-70 to cycle longer rounds is required.  Both cartridges (WWG 457 Magnum in a WWG 457 Magnum conversion and 45-70 in a Marlin 1895 45-70 altered to cycle a longer round) have a cartridge overall length of up to 2.67".

Hope this helps.

I don't know what the 308MX has to do with the WWG 457 Magnum.

[S.B.]

Now, I am confused. Did you answer my questions? Is it or isn't it necessary to increase the length of the chamber? Some times I think you guys really like to hear yourself talk. Just a yes or no would work for me. Sorry I asked.

[efremtags]

Can hardcast ammo practically be loaded longer in 45/70 brass. Will it miss the crimp grooves.

If hornady sold their 325gr leverloution bullet, loaded to 2.67OAL, that would be some ammo.  This would probably be the most practical hunting ammo available for the 45/70 because of the improved BC. The major limitation is speed doesn't buy you much from the calculations above because of the terrible BC of the flat point round. Hornady loads factory ammo down so the factory stuff is not that impressive compared to whats it is capable of.

I have to start shopping around for a used gun to modify. I hate to touch my current GG as it shoots great as is.


 

[EsoxLucius]

Is it or isn't it necessary to increase the length of the chamber?

For the Wild West Guns 457 Magnum conversion, yes.
For modifying a Marlin 1895 45-70 to cycle a round up to 2.67", no.

I thought I couldn't have made that clearer above.

Sorry I wasn't helpful and apparently wasted my time trying to explain it.

[big medicine]

What the heck?? I was on the the thread about the 358/356 conversions and posted about the 308MX how it ended up here I have no idea sorry.

[quickdtoo]

What the heck?? I was on the the thread about the 358/356 conversions and posted about the 308MX how it ended up here I have no idea sorry.

Dunno, but that's where it is now!!

Tim

[big medicine]

What the heck?? I was on the the thread about the 358/356 conversions and posted about the 308MX how it ended up here I have no idea sorry.

Dunno, but that's where it is now!!

Tim

thanks!!!

[S.B.]

big medicine, I've had Gremlin attacks lately on this website, also?

[Icy Straits]

EsoxLucias- I Thought that was a very informative and interesting reply on the difference between the rounds. Thanks for taking the time.